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Guidelines for Real Estate Research and Case Study Analysis
Book · January 2016
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           Ranthilaka Gedara Ariyawansa                                                                           Terans Gunawardhana
           University of Sri Jayewardenepura                                                                      RMIT University
           97 PUBLICATIONS 211 CITATIONS                                                                          48 PUBLICATIONS 62 CITATIONS
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1
Guidelines for Real Estate Research and Case Study Analysis
Published by the Department of Estate Management and Valuation,
University of Sri Jayewardenepura
ISBN 978 955 4908 42 0
R. G Ariyawansa
Professor
Department of Estate Management and Valuation
Faculty of Management Studies and Commerce
University of Sri Jayewardenepura
Sri Lanka
135/60 A, Jaya Mawatha,
Neelammahara Road,
Maharagama
ariyaw71@sjp.ac.lk
W.H.T. Gunawardhana
Lecturer
Department of Estate Management and Valuation
Faculty of Management Studies and Commerce
University of Sri Jayewardenepura
Sri Lanka
Email : terans@sjp.ac.lk
TP     : +94713238188
31.01.2016
                                2
                             Contents
Content                                      Page No
Chapter one: Introduction to Real Estate                     07-20
   Land
   Real Estate
   Real Property
   Types of Properties
   Real Estate Development
   Real Estate Management
   Real Estate Valuation
Chapter Two: Real Estate Research and Case Study Analysis
                                                            21-46
      Beginning of a Research
      What is a Research?
      Types of Research
      Real Estate Research…!
      Researcher
      The Research Process
Chapter Three: Real Estate Analysis-Quantitative Approach 47-87
   Hypothesis Testing
   Selection of an appropriate statistical test
                                 3
Chapter Four: Real Estate Analysis- Validity and Reliability 88-96
   Validity of Research Outcomes
   Reliability of Research Outcomes
      Bibliography                                        97-98
      Glossary                                            99-127
                                 4
Purpose of the book
Real Estate Development and Management (REDM) is multi-
disciplinary in nature. Therefore, the scope of Real Estate
Development and Management is very wide and complex. This
discipline relates with several subjects as well. Any decision
taken by a supplier, buyer, investor, policy maker etc is very
crucial and expensive. Changing or altering decisions is
sometimes impossible or very expensive. Therefore, scientific
analysis is a fundamental requirement for the correct decision
making process. Scientific research also helps for innovations
in the industry.
Hence, this book attempts to provide some basic guidelines for
real estate research and case analysis. The book briefly
describes about some fundamentals of real estate, real estate
research and case analysis. For comprehensive analysis,
however, it is needed to aware sufficient knowledge on related
subjects such as Real Estate Development and Management,
Marketing Management, General Management, Micro and
Macro Economics, Valuation, Law and Planning and research
methods etc. Followings are some of fundamental areas that
should be comprehended by developers, managers and related
professionals such as planners and valuers etc.
     Principles of Real Estate Development and
        Management.
     Classification and Identification of Different Properties.
                                5
 General Management (aspects including four functional
  areas i.e. Financial Management, Human Resources
  Management, Production and Marketing Management).
 Strategic Management.
 Role of different stakeholders i.e. developer, investors,
  managers etc.
 Analysis if highest and best use of lands and properties
 Cost Benefit Analysis.
 Cash flow, Net Present Value, Internal Rate of Return
  etc with regard to real estate investment projects.
 Investment appraisal and portfolio management.
 Real Estate Development process, real estate life cycle.
 Property and the macro-economy, globalization of
  properties.
 Obsolescence of properties and remedies.
 Different costs and values in real estates.
 Environmental effects on Real Estate and vice versa.
 Building facilities & service management.
 Management of Condominiums.
 Ownerships, tenure types, different interest and legal
  aspects of real estates.
 Real estate management in non-real estate firms i.e.
  Corporate Real Estate Asset Management (CREAM).
 Review of real estate industry and public policy (real
  estate sector/real estate markets etc).
 Real estate research and consultations.
                            6
                         Chapter 01
                  Introduction to Real Estate
Some Basic Concepts
There are three major terms to be clarified firstly in the field of
real estate. They are;
    - Land
    - Real Estate
    - Real Property
    - Types of Properties
    - Real Estate Development
    - Real Estate Management
    - Real Estate Valuation
Land: Land is defined as the earth’s surface extending
downwards to the centre of the earth and upwards to infinity,
including things permanently attached by nature such as trees
and water. The term “land”, thus, refers to not only the surface
of the land but also the underlying soil and things that are
naturally attached to the land, such as rocks and plants. Land
includes the minerals and substances far below the earth’s
surface. It also includes the air above the land up into the space.
Therefore, land consists of three layers known as respectively
the “surface” the “subsurface” and “airspace”.
Land is one of the basic factors of production. Primary
production functions are taken place in rural land (non-urban
land) whereas the other functions are allied with urban
                                 7
locations. However, due to the development of the
infrastructure facilities, it is difficult to demarcate urban uses
and non-urban uses easily. Anyway, in this book, more concern
is given to urban property development and management.
Real Estate: Real estate is defined as the land above and below
the earth’s surface, including all things that are permanently
attached to it either natural or artificial. Therefore, the term
“Real Estate” is broader than the term “land”. It includes not
only the natural components of the land but also all artificially
improved immovable features made by the man.
Any artificial thing that is attached to the land, such as a
building or a structure or a fence is concerned as a part of real
estate. Land is also converted into real estate as it is improved
by means of providing access, utilities, sewerage systems and
other services that make it suitable for habitable buildings. They
are also called serviced-lands, improved lands or developed
lands. Such parcels of lands are called real estates since they
have been reshaped from their natural features.
At the same time, it is clear that the land becomes usable when
it is converted into a real estate. This means when a land
becomes a real estate, it is usable for planned activities.
Therefore, it is able to argue that the “usability of the land” is a
more apparent and logical criterion to recognize real estate. In
this way, it is also able to argue that when the man starts to use
the land it becomes a real estate.
                                  8
Real Property: The word “property” has different meanings in
legal term1. In this discipline, it is the land and tangible features
on the land and permanent improvements.
“Real property” is defined as the interests, benefits and rights
inherent in the ownership of real estates. Indeed, a real estate is
valuable, usable and marketable as it possesses several real
properties. Hence, the term “real property” is broader than both
the terms “land” and “real estate”. It includes the physical
surface of the land, what lies above and below to it, what is
permanently attached to it, as well as the bundle of legal rights:
legal rights of ownership which is attached to the ownership of
a parcel of real estate.
Real property includes not only the surface, subsurface and
airspace but also the surface rights, subsurface rights and
airspace rights, all of which can be owned by different
individuals. There are, however, some limitations as well. For
instance;
         Surface rights are restricted by different legal conditions
          such as Planning Law which aims to control haphazard
          development, Law of Delict, which aims to protect
          others from nuisance made by one who enjoys benefit(s)
          of a real estate etc. Further, restriction of cutting some
          trees like jack, coconut etc, and excavation of sand,
1
    Moveable property, immoveable property etc… In this subject, the term
    property referred only to immoveable properties.
                                    9
       granite etc are examples of limitations of the surface
       right.
      Subsurface rights are restricted by licence, tax (for
       instance gem mining) while some substances are fully
       restricted by having state ownership such as fossil oil
       and some minerals etc.
      Airspace is also restricted by civil aviations law,
       electricity and other service lines etc. Further, it seems
       in many countries of full restriction for fling by
       individuals or need of very special permission for some
       selected journeys.
Land = (Soil) + (All natural attachments up to the space and
         below to the centre of the earth)
Land = (Natural Surface) + (Natural Subsurface) + (Natural
        Airspace)
Real Estate = Land + All Man Made Fixtures
Real Property = (Real Estate) + (Rights and benefits attached
                     to real estate)
                               10
Classification of Properties (Types of Properties)
When it is analysing the real estate cases, it is essential to know
different types of properties. Properties can be classified
according to different criteria as pointed out below.
Law classifies properties based on the ownerships/tenure as,
         Freehold
         Leasehold
         Customary
As per the property usages/nature of development properties
are classified as,
         Residential property/ condominiums
         Commercial property
         Agricultural property
         Public property
         Industrial property
         Service property
As per the ownership, it is classified as;
         Private (individuals, companies and social
            organizations etc)
         Public (state departments, incorporated bodies etc)
According to the location, neighbourhood development etc,
properties are classified as;
        Urban property
        Rural property
                                 11
Markets and related socio-economic context may define
properties (especially residential properties) as,
        Luxury
        Semi-luxury/ middle income...
        Low income etc
Some more special classifications can be made if needed. For
instance, properties can be classified according to the age,
materials used, technology adopted, value, size of properties
and so on. Hence, property related cases may come under these
types of properties and their characteristics. (For property
characteristics, read the Chapter one, Management of Real
Estate...by R G Ariyawansa pp.8-15).
Real Estate Development (RED)
“Real estate development is an idea that comes to completion
and use the bricks and mortar put in place by the
development team (Mike et. al., 1995)”.
The above definition can be rephrased as “Real estate
development is a refined and confirmed idea that comes to
satisfactory completion and satisfactory use of right bricks and
mortar put in place by the specialised development team”.
This definition implies that the real estate development is not a
single or a simple activity. It is a long term process. Also it is a
continuing process. It is a number of activities. It has three main
processes such as,
                                 12
       (a) A process of “idea generation”
       (b) A process of “physical construction” and
       (c) A process of “use of the built property”
It needs a team of experts to complete a development. Whatever
the effort put into a development, it is worth only if the final
product is usable, funtionable, and adoptable to satisfy the
different and changing needs and wants of different users of the
property. Therefore, the idea of acquiring a particular property
should be refined and confirmed having properly done “need
analysis”. Completion of the project should be properly
monitored not allowing any deviation from the expected needs
and wants but having necessary alteration according to altered
needs and wants if any in order to maximise the users’
satisfaction.
The development team is responsible to select the right input
(bricks and mortar) to realize the expected needs and wants. It
seems that the “completion” of the development is not met by
the completion of physical construction alone. Actual
completion means that the physically constructed structure
becomes a property only if it is fit for the continuous use for the
beneficiaries’ satisfaction. Therefore, it is clear that the real
estate development is linked with the real estate management.
                                 13
Real Estate Management (REM)
Property management starts with the property purchase idea
(idea of acquiring/ building/ purchasing or simply having a
property) of the users and investors. Generally, there are two
main areas in property management. They are,
      Property portfolio management.
      Property assets management.
Property portfolio management is dealing with strategies of
formalising and monitoring of an organization’s property so as
to achieve the maximum portfolio return and minimum
portfolio risk. Hence, this mainly deals with the financial and
investment decisions in connection with real estates (land and
landed properties) at the strategic level of organizations. For
instance, critical decisions relating to properties such as
acquiring, constructing, changing the uses and users, and
demolishing or selling properties etc are highly expensive for
organizations. And also implications of such decisions for the
entire organizational activities are very high. Therefore, such
decisions are usually taken by the top management as they are
strategic level decisions.
“Property asset management” is about the use of properties in
maximum level. Therefore, it deals with the objectives of
increasing the life span of properties together with the
contribution to economic worth of the assets. Hence, through
property assets management, organizations expect to ensure
                               14
proper care and attention of benefits of properties. Thus,
property assets management functions deal with the operational
decisions. These decisions are usually taken by the middle and
lower level managers of organizations.
In case of properties of private sector organizations, it is
expected to have separate property management plans along
with the corporate business plans of organizations. As far as the
management of the public sector properties are concerned, there
may have some approved laws relating to the respective public
sector agency. Sometimes, necessary regulations and circulars
are issued time to time and strategic level and operational level
decisions are taken accordingly. Decisions according to
circulars are not rational as it does not always concern the
professional requirements rather than administrative
requirement.
   (1) According to the RICS policy review in 1974, the Estate
       Management (The generic activity) is considered as “All
       facets of case, development and Management of urban
       land, including the sale, purchase and letting of
       residential, commercial and industrial property and
       management of urban estate and advice to clients to
       planning …
Further, the areas of Corporate Real Estate Asset Management
(CREAM), Real Estate Facility Management, Real Estate Life
Cycle Management, Management of Farm Land, Management
                                15
of Public Properties etc are some of areas under the subject of
real estate management.
Some issues relating to the increasing real estate assets of
organizations
         Rapid changes in technology: This is beneficial as
            it paves the way for innovations, highest and best
            uses etc. At the same time, it is a challenge as it
            leads to a heavy cost and functional obsolesce of
            properties etc.
         Variety of social needs: Since social needs and wants
        are rapidly changed, adoptability of properties is an
        expensive task.
          Unforeseen expensive maintenance problems: This
           may collapse property functions interrupting all
           operations of organizations.
          Continuous management needs: To minimize the
           above risk, it incurs heavy cost for overall property
           management.
          Having properties without interested parties/
           clients/ demand: This pushes organizations to be
           bankrupted due to unbearable property cost.
The above mentioned are general challenges for any
organization. Organizations can only be able to face these
challenges by applying proper management for real estate.
                               16
Similarly, organizations have to deal with some common
macro-economic issues when managing properties.
Some macro level socio-economic issues
        Interest rates over the cost of money.
        Inflation on construction cost.
        Tax/ subsidies etc.
        International trading issues.
        Establishing international property market.
        Oil crisis/ cost of energy/ electricity/ gas etc.
        Scientific development.
        War/crisis/ natural and artificial disasters.
        Ultimate result of determinants of property prices:
           difficult to renew/ difficult to test/ difficult to focus.
Decision making is challenging
As explained in above sections, it is clear that real estate and
related socio-economic context is very dynamic and
challenging. Especially for some decisions related with real
estate, expert views with proper analysis are essential.
Followings are some of examples for which scientific analysis
are needed.
     Real estate restructuring, especially for large
        organizations.
     Real estate (new) development or redevelopment.
     Estimate values of real estate for different
        transactions/purposes.
     Property auditing for necessary changes.
     Research for searching new knowledge.
                                  17
      Preparing real estate strategic plans to support general
       business plans of large organizations.
      Real estate brokerage when selling or purchasing.
      Capital markets/asset advisory for investment
       management.
      Feasibility studies, property analysis for new investment
       or alteration for the existing real estate.
      Evaluate customer needs and to solve customer
       problems.
      Etc...
Why real estate projects need experts’ views?
   As real estates are multi-disciplinary by nature, single or
      few cannot complete projects.
   Complicatedness of real estate is another aspect for
      which developers/manager/buyer/seller/policy makers
      need to have scientific information based of
      comprehensive analysis.
   High risk should be minimized and high cost should be
      controlled through correct information.
   Durability of investments on real estate is very long and
      therefore the decision making is high responsible task.
   As overall social cost of real estate is very high.
Namely, there are some common studies required in real estate
projects such as,
     Appraisal/Valuation.
     Cost-benefit analysis.
                               18
      Analysis of economic base of real estates or businesses.
      Analysis of economic impact.
      Study of highest and best use of land and properties.
      Land use study in regions or neighbourhoods.
      Market surveys.
      Marketability study.
      Financial feasibility.
      Environmental impact analysis
Real Estate Valuation
Ensuring highest possible value of a real estate is one of sine
qua non in the process of real estate development and
management. Values of a real estate may be estimated for
different purposes such as buying or selling, taxation,
compensation, mortgaging, insurance, and accounting purpose
and so on.
In the process of estimating values, observation of property,
collection of data, analyzing, and writing reports and
presentation (if necessary) are all challenging tasks for valuers.
This is due to properties are living entities, business entities,
built environments, eco-systems, social systems, not just
physical entities.
However, the estimation and final judgment of the market value
of a property is heavily based on an individual’s opinion. This
means that individual’s views, experience, knowledge,
attitudes, beliefs etc. will operate as internal determinants when
                                19
he/she engages in observing properties, auditing properties,
collecting, reporting, and analyzing data for the purpose of
estimating the market value of a property. Hence, providing
objective opinion is a crucial task for a valuer as a human being
who is living among ordinary community. However, it is
believed and also evident that by means of wider experience,
updated scientific knowledge, a range of smart skills as well as
professional ethics, cord of conducts etc. an ordinary/apprentice
valuer (learner) is developed as a capable, confident
professional who is conscious over the existence of the given
property and the property market enabling to take correct
judgments based of proper analysis.
                                20
                        Chapter 02
       Real Estate Research and Case Study Analysis
This chapter consists of two sections as “Beginning of a
Research” and “Designing of a Research”.
Beginning of a Research
Introduction
How do you find an answer(s) for a problem(s)? There are
several approaches for this. Mainly,
   (1) Informal/personal/ad hoc/conventional/ indigenous
       approaches.
   (2) Technical/legal/procedural/expert-opinions/democratic
       approaches.
   (3) Systematic/purposeful/concerned/rational/scientific-
       approaches, (which is called RESEARCH).
The first approach is very general, ordinary people tend to
apply such methods for solving issues as a practice or habit or
due to ignorance. However, the rate of successful results is very
small.
The second approach is somewhat systematic. However, to
solve a crucial problem this approach may not be enough.
Mostly the first and second approaches attempt to find solutions
for symptom not for the root cause of issues.
                                21
The third approach is stronger to find solutions for real problem
as it addresses the root of the problems. This approach is;
      Base on philosophy/theory.
      Least bias.
      Least subjective.
      Higher ability to generalize.
      Higher degree of applicability.
      Measurable/responsible/correctable/improvable.
      Higher reliability and validity.
What is a research?
In order to find an answer for the above question i.e. what is a
research, try to find answers for the questions mentioned below.
     Why do you want a research?
     How do you do research?
     When do you do research?
Research cycle: What/Why/How/When …research?
Simply research is an attempt to find solutions for a problem.
The nature of the problem for which research is needed to find
solution is a considerably a long term socially painful matters.
Therefore, it needs a purposeful, conscious and systematic
attempt. Sometimes, it needs a very specific method for a
specific problem. Following diagram illustrates what/why/how
and when a research is done.
                                22
Research cycle
        Origin of research:                       Societal problems:
    There are questions/issues/             These are multidimensional/
   difficulties/needs and wants/            interrelated/ interdependent/
  motivations/ frustrations/desires/        critical in situations/ multiple
      expectations/plans etc.                            views.
                                                A need: to solve such
     A Process of Research:
                                                       problems
   An application of systematic                     systematically,
    inquiry using relevant and                       scientifically,
  adequate data/information with                rigorously, rationally,
  a view to find ways and means                   using relevant and
                                                       valid data
   of solving the given problem
Every individual and group as well as family and firms have
different problems, needs and wants etc as mentioned in the top
left-side box. These issues become social problem gradually as
all individuals and organizations are interacting with other
members of society. That is why it needs to have systematic,
scientific and rational approaches to address to such social
issues. In fact, it needs “an application of systematic inquiry
using relevant and adequate data/information with a view to
find ways and means of solving the given problem”. These
underlined terms are important to understand the meaning of
“research”.
                                       23
Systematic inquiry: This implies a profound design of a
research. Identification of the problem, establishing aims and
objectives, setting research questions, review of literature,
determining variables, research tools, and analysis etc; are the
features of a systematic approach.
Relevant and adequate data and information: This means
that you want to make sure the validity and reliability of your
study. The data used should be relevant to find the real picture
of the situation. And also you need to use adequate amount of
data to obtain reasonably accurate results.
Ways and means: This implies that by a research you are
supposed to add new knowledge to the existing body of
knowledge.
Accordingly we can define research as mentioned below.
Definition for research
A research is a way of thinking and action in inquiring a
problem/issue/need … with a view to find solution or to find a
way of satisfying the need in a higher level.
The way should be:
    Scientific:- measurable, justifiable, applicable,
      approachable, feasible.
                               24
     Least subjective (objective) and nonbiased.
Thinking and action:
This implies that the whole process of designing, collecting
analysing and interpreting data, drawing conclusions, writing
the report, and presenting of the finding.
Problems/issues/needs:
    Why/how/how much/how many/ when/ and so on are
       problems.
      You can think and identify researchable questions
       relating     to      suitable     procedures/     rules/
       regulations/practices/      norms      and       values/
       attitudes/methods/criteria/            formats/formula/
       mechanism/processes etc.
Higher level:
This is very significant in a research. This emphasises that you
are producing a set of new knowledge. Otherwise whatever
your attempt will not be a research.
Therefore, remember research is not the SPSS or any other
computer applications or the final report. It is a series of
activities from identification of a problem/need, and meeting
and discussions with experts/supervisors/ reviewing of relevant
literature/ collecting, analysing and interpreting data and
information/ writing a report/ presentation of finding and
justification for the findings etc. Also the end of your research
                                25
is the beginning of another research(es). The research process is
generally a cyclical one.
Types of research
   (1) According to the nature of what do you want to do,
       research can be identified as,
           a. Descriptive research:
              You describe a situation or the nature of a
              problem in this approach. You describe what is
              the shape of the problem? For instance, (i) Study
              on the changes of land use pattern in Colombo
              city. (ii) An empirical examination of socio-
              economic characteristics of slum dwellers in
              Colombo.
           b. Correlation research:
              You examine the relationship(s) between (or
              among) variables. (With what it is related). For
              instance, (i) Analysis of the impact of new tax
              policy introduced by the 2008 budget on the land
              use in the Western Province. (ii) Analysis of the
              effectiveness of application of computer
              technology for planning in Sri Lanka.
           c. Explanatory research:
              You study why a certain problem or a
              phenomenon or a situation or a relationship etc.
              exists. (Why it is related with that). For instance,
              (i) Why the rate of increase of land price is
              higher in Colombo than major Asian cities? (ii)
                                26
           Factors for the success or failure of privatization
           of state owned investment properties.
(2) According to the major discipline, you may find a
    classification of research as,
        a. Research in pure sciences:
            For instance, (i) A successful medication for
            cancer patients. (ii) Impact of soil types on
            building cracks.
        b. Research in social sciences & Humanities:
            This is generally recognized as Social research.
            For instance, (i) Study of the food behaviour of
            cancer patients. (ii) Building cracks and
            developers’ responsibility.
(3) According to the use of the research, you may find a
    classification as,
        a. Pure research:
            These are the researches about the research
            methodology. For instance, (i) Developing
            appropriate criteria for suitable sampling for land
            use analysis.
        b. Applied research:
            Research relating to a project, development of a
            product or a service etc is an applied research.
            For instance, (i) Pattern of land price of
            peripheral agricultural land in Colombo. (ii)
            Changes of small scale constructions after the
            Tsunami devastation in Southern Sri Lanka.
                             27
(4) According to the style of inquiry you find types of
    research as,
        a. Quantitative research:
           In a quantitative research, you use data from
           highly structured formats and analyse
           accordingly. For instance, you quantify
           relationships, classify relationships, order
           relationships according to the significance,
           compute ratios, use specific samples, and so on.
        b. Qualitative research:
           In qualitative research, you use data and
           information in unstructured forms and analyse
           accordingly. There, you describe the variables
           and their relationships rather than quantifying,
           use selected cases for in-depth analysis and so
           on.
       c. Hybrid / combination of qualitative and
          quantitative research:
          This is a mix of qualitative and quantitative
          methods. Therefore, this is more practical and
          useful method.
(5) According to the research paradigms, you find different
    types of research as,
        a. Systematic or Scientific/ positivist approach.
        b. Qualitative,    ethnographic,     ecological   or
           naturalistic approach.
                           28
Therefore, it is clear that there is no a hard and fast
method/methodology called “the methodology”. Determine a
suitable method for your particular study. Then that particular
method will be “the methodology” for your particular study for
that particular purpose, in that particular occasion.
Real Estate research…!
According to the basic production circular model, you can think
of either the producers’ aspects or consumers’ aspects relating
to real estate as depicted below.
General consumer production circular model
                        Household Consumers
                         Producers Suppliers
                             Research on
 Real Estate Producers/suppliers’          Real Estate Consumers’ point of
           point of views                                 views
 Financial/investment aspects            Pattern of consumption, needs and
 Market/marketing/business/invest         wants
  ment/products and services, new         Satisfaction
  products/innovations etc                Income and expenditure patters
 Environmental/material/procedure        Socio-cultural
  s/ standards etc                        Political aspect
 Cost and value of products and          Demographic
  services                                Different users, households,
 Economic aspect/ policies/               neighbours, visitors etc
  development projects                    Consumer behaviours
 Legal aspects                           Psychological aspects
 Technical aspects                  29   Knowledge, belief, values etc
 Professional aspects
 Management aspects ...
It can be described research as a process of collecting,
analysing, and interpreting information to answer questions.
However, answering for research problems can be made
according to the different perspectives and different angles. For
instance, go through the following examples.
   (1) Why do people pay lower amount of stamp duty on land
       transaction? You will find different answers for the
       question as follows.
        Answer 01 is “In order to minimize the cost”. This
           answer seems as a customer point of view. It is an
           economic aspect relating the problem.
        Answer 02 is “Since they don’t know the legal
           actions against the fraud”. This may be a
           professional’s point of view. It is a legal aspect
           relating to the problem.
        Answer 03 is “Due to the weakness of the market
           system, immaturity, informality”. This seems as an
           academic’s point of view. It also looks like a policy
           aspect relating to the problem.
Similarly you can learn the following examples and you will be
aware of formulating research theme as well.
      How does the existing information system help to the
       role of the valuer?
      What is the appropriate plot size for residential
       properties in Colombo city?
                                30
      The appropriateness of plot size and different land uses.
Researcher
In order to make an appropriate analysis, real estate researcher
will have some qualities such as;
      Researcher is (or will be) an expert in a particular area
        of interest in the field of real estate.
      Lifelong learner.
      Self learner.
      Good consultant.
      Able to diagnose problems accurately.
      Rational thinker.
      Good negotiator.
      Good observer.
      Able to provide objective opinions.
      Philosopher.
      Theory builder.
      Opinion maker.
      Good rapport builder.
      Good investigator.
      Able to read and comprehend.
      Listener.
      Writer.
      Analyser and interpreter.
      Presenter and convincer.
                               31
The research process
(1) Identification of a research problem.
          Tentative Title
        Area of study                        This shows you a
                                      direction/destination and hints
                                        you about the needed data/
                                        sample/analysis type etc. to
            Reviewing                formulate an attractive title and a
             literature                    good research design
         Research problem
(2) Research design:
      Your own way of activities in the research.
      You have to plan everything systematically.
        rationally/logically such as,
            o Data/ data collection methods.
            o Sample/sampling strategy.
            o Analysis types.
            o Timeframe/cost etc.
            o Limitations/policies/scope etc.
                                32
(3) Preparing data collection tools.
      Observation methods/guidelines.
      Interview schedules/ list of interviewees/ organizations
        to be visited etc.
      Interview guidelines.
      Questionnaire(s).
      Data recording tools.
(4) Selecting a sample(s)/cases.
     Representing the total population.
     Consider the cost.
     Within the given or available timeframe.
     According to the purpose of the research (objectives).
(5) Research proposal.
    Arrange what you have done so far as an informative
    document, which guides you to conduct the research. This
    tells your supervisor and the finding agency about what and
    how you will do in your research and what sort of outcomes
    will likely be there.
   Therefore, you have to include followings in your research
   proposal.
     Title.
     Introduction (an argument along with theoretical
       briefing).
     Statement of the problem.
                               33
        Objectives (General and special).
        Hypothesis (if needed).
        Research design (methodology).
        Limitations/scope.
        Chapters of your research report.
         (These features are enough for BSc and MSc level
         academic research proposals)
        Timeframe.
        (PhD and other given task, even for MSc programs if
        requested)
        Budget.
        Qualifications of resource persons (CVs).
        Any other relevant particulars.
        (For funded projects)
(6) Collection of data and information.
(7) Analysis of data.
(8) Writing a report.
(9) Presentation and justification of findings.
(10) Preparing for publication of papers in journals or as a
    book.
Learning outcome up to now
The following table summarises the learning outcomes that you
have gained up to now from the first part of this chapter.
                               34
Learning outcomes
Our attempt       Your responsibility                 Learning
                                                      outcomes
We attempt to         Knowing answers for
                                                      Short term
help you to           (1)-(5)
understand            You will be
(1) What is           researchers and you do
    research?         research (Research
(2) How do you        oriented/analytical/
    do research?      good observer/
(3) Who is            maintaining your own
    researcher?       data and information
(4) What              bank/ innovator/
                                                      Long-term
    characteristic    critical thinker/ theory
    s does a good     builder)
    researcher        Accordingly you help
    have?             to upgrade the social
(5) What is the       well-being through
    purpose of        being a true real estate
    doing a           professional
    research?
Designing of a Research
This part of the chapter 09 covers following areas.
    Designing a research proposal.
    Title of your research.
    Developing an “Introduction”.
                                35
      Methodology.
      Designing of your research.
Designing a research proposal: You need to have an
appropriate research proposal to conduct a research. Research
proposal is the outcome of the process of “research design”. If
you have a sound proposal, you have finished 1/4 or 2/3 of your
research.
Title of your research: This is the “theme/topic” and/or “the
shortest possible meaningful way of expression of your research
study” by means a “name”. However, you do not necessarily
need a title to begin a research. Constructing a title is a part of
the research designing process. Title preferably possesses some
characteristics such as;
      A very short phrase but not a sentence.
      Clear and straightforward meaning and eye-catching.
      Maximum two to three lines.
      It should imply (highlight/hint) the core of the research
       problem and the area of the study.
      Avoid two or more research problems (avoid
       conjunctions such as “and”, “or” etc…).
      Not necessarily be in a form of questions (What, when,
       why…etc), better avoid from questioning.
      Should not be in a form of exclamation/
       sympathy/emotion (!, Oh !, …).
                                 36
      Should not include abbreviation/ jargons/ ambiguous
       terms (WHO, CMC, UN…).
      Should not be two sentences, but able to have one sub
       title not more than one.
Followings are examples indicated in the first part of this
chapter.
    1. Study on the changes of land use pattern in …
    2. An empirical examination of socio-economic
        characteristics of slum duellers in…
    3. Analysis of the impact of new taxes imposed by the
        2008 budget on land use in the Western province
    4. Analysis of the effectiveness of application of computer
        technology for planning in Sri Lanka
    5. (Why) the rate of increase of land price is higher in
        Colombo than major Asian cities
    6. Factors for the success or failure of privatization of state
        owned investment properties
    7. A successful medication for cancer patients
    8. Impact of soil types for building cracks
    9. Food behaviour of cancer patients
    10. Building cracks and developers responsibility
    11. Developing (suitable criteria for ) a suitable sampling
        for land use analysis
    12. Pattern of land price of peripheral agricultural land in
        Colombo
    13. Changes of small scale constructions after the
        Tsunami devastation in Southern Sri Lanka
                                 37
   14. Why do people pay lower amount of stamp duty on land
       transaction?
   15. How does the existing information system help to the
       role of the valuer?
   16. What is the appropriate plot size for residential
       properties?
   17. The appropriateness of plot size and the land use
Go through the following questions and answers carefully.
Question 01: Are these appropriate titles for research and can
           you do researches on these areas?
Answer: These are not in the form of attractive titles. However,
         each shows an appropriate area for research.
Question 02 – How do I formulate a good title out of these?
Answer – Simply you can do it by rephrasing the given themes!
         However, it is not too simple as it says. Before
         rephrasing or rearticulating, learn the way you
         extracted the theme. It is none of the way other than
         scanning of the existing literature. Therefore, you
         have to adopt the same way to develop a
         researchable theme into an appropriate title i.e. with
         the help of reviewing relevant and updated literature.
         It may be possible if you are smart in language.
         However, without knowing the existing situation
                               38
           you can not do a research. You will not go
           ahead…!!!!
Examples 01
Suppose that you have roughly identified a research theme as
“Analysis of Housing Market”. This is a relevant researchable
area in your discipline. But, it is too vague. So, you have to
rearticulate it to be a specific and researchable theme. Go on the
following steps and learn the gradual changes made for the
initial theme.
     a) Analysis of Housing Market
     b) Analysis of Housing Market in Colombo
     c) Analysis of Housing Market in Colombo and Suburbs
     d) Analysis of Consumer Behaviour of the Housing Market
         in Colombo and Suburbs
     e) Analysis of Determinants of Consumer Behaviour of the
         Housing Market in Colombo and Suburbs
     f) Analysis of Determinants of Consumer Behaviour of
         Potential Buyers in the Housing Market in Colombo and
         Suburbs
     g) Analysis of Determinants of Consumer Behaviour of
         Potential Buyers in the Housing Market in Colombo and
         Suburbs
     h) Analysis of Determinants of Consumer Behaviour of the
         Housing Market in Colombo and suburbs: Views of
         Potential Buyers
                                39
   i) Analysis of Determinants of Consumer Buying
      Behaviour of the Housing Market: Views of Potential
      Buyers in Colombo and Suburbs
   j) Determinants of Consumer Buying Behaviour of the
      Housing Market: Views of Potential Buyers in Colombo
      and Suburbs
   k) Analysis of Determinants of Consumer Satisfaction of
      the Housing Market: Views of Potential Buyers in
      Colombo and Suburbs
   l) Analysis of Determinants of Consumer’s Expected
      Needs and Wants from of the Housing Market: Views of
      Potential Buyers Evidence of Colombo and Suburbs
Example 02
Initial title
“Impact of global credit crunch on residential property market
in Sri Lanka with special reference to Kaduwela area in
Colombo”
Improved titles
“Impact of global economic downturn on residential property
market in Sri Lanka: Empirical evidence from Colombo”
“Impact of failure of global financial market on residential
property market in Sri Lanka: Empirical evidence from
Colombo”
                              40
“Failure of global financial market on residential property
market in Colombo: Competition of global and local contexts”
Some special lessons….
    Having a small area makes your work easier but smaller
      area will make you an empty feeling and not
      encouraging (for beginners).
    Having connections with few other areas and the major
      area provides you more opportunities to expand your
      expertise.
    Having a vague, unfamiliar area will stop your journey
      or mislead or fed up.
    Having many connections with the major area will make
      you more ambitious, more workload, and ultimately you
      will have less or no focus.
Developing an “Introduction”
Suppose that you have finalized a title as, “Determinants of
Buying Behaviour of the Housing Market: Views of Potential
Buyers in Colombo and Suburbs”. Accordingly you have to
provide an “INTRODUCTION” to your study at the beginning
of the proposal. What does the “introduction mean? What is it
supposed to do?
Different people may have different understanding and/or
different levels of understanding over a title/theme according to
their perceptions. Therefore, you have to show very clearly
what your perception over the title/theme with the help of
                                41
analyzing the background. It is an overview of your study. You
describe all the core areas of your research theme. According to
this example, “buying behaviour”, “determinants of buying
behaviour” “potential buyer” “housing market” are core
concepts in the study theme. You need to develop a core
ideology/ theme/ logic/ rationale or a central argument for your
study by means of the introduction. Through this way, you trace
a “research problem” more specifically for your study. And at
the end of the introduction you can indicate the research
problem of your study under a separate heading called
“Statement of the Problem”.
In the introduction,
     You have to discuss all the major concepts of your
        research theme/title.
     For instance, according to the first example, “Consumer
        buying behaviour”, “Housing market in general”,
        “Housing market experience of Colombo and suburbs”
        are major areas of importance.
     Therefore, in your introduction, you have to describe all
        these concepts according to their level of significance.
     You should identity and discuss the relationship
        between/among these concepts (major concepts and
        their variables).
     You have to input sufficient amount of literature
        (evidence) to support your argument along with
        citations in an appropriate way.
                               42
Once you precisely identified a research problem, you can go
ahead with your research by setting aim(s) and objectives
through which you can address the research problem. You can
have one general objective and few specific objectives.
However, this is not a must.
Having some research questions on specific objectives
commonly or separately, you can easily simplify your study
further so that you can find solutions for the research problem
from a particular point of view of your interest.
Methodology
You need to describe particularly the data on which you depend
in finding solutions for the research problem. (Instead of that, it
is needed to explain data collection and analysis methods,
limitations etc).
Designing your research
Step 01- Through reviewing literature (relevant concepts,
        theories, research findings, models, procedures,
        practices, definitions, statistics and so on), you have to
        trace a researchable problem.
Step 02 – Scale-down the scope of your area of study into a
        very specific, least complicated, meaningful, and
        researchable. This is possible by means of formulating
        general and specific objectives, research questions for
        each specific objective (if needed), adopting some
                                 43
         limitations relating to the variables, case studies,
         samples for data collections, methods of analysis etc.
Go through carefully the following table and facts in it. You
learn the total activities of designing your research as discussed
in the chapter.
Examples - 01
Specific      Research           Yardstic       Data/informat
objectives    Questions          ks     of      ion (working
(About        (Using             indicator      definitions of
particula     indicators         s              variables)
r             of relevant        (relevant
concepts      concepts)          variables
relating                         of
to the                           indicator
research                         s)
problem)
Househol       Distance         About the      About size of
d’s desires     to service       quality        rooms,
or              centres          of              Size       of
satisfactio    Quality of       structure         bedrooms
n               structure        s,              Size of
                s (What           Design          kitchen
Objective       specific            s            Size       of
is,             features          Size of         bathrooms
To              does a              rooms        Size       of
evaluate        buyer             Qualit
                                44
household       expect         y     of      sitting
’s desires      from a         finishe       rooms
on              house in a     s           etc.
different       flat?)        Materi     (These are the
features of    Neighbour      al used    expected set of
a house.        hood          etc.       data. You can
                quality                   obtain needed
               etc.                      data through
                                          observation,
                                          questionnaire,
                                          interviewing
                                          experts or
                                          secondary
                                          sources)
Examples - 02
Specific      Research       Yardstic     Data/informat
objectives    Questions      ks      of   ion (working
(About        (Using         indicator    definitions of
particula     indicators     s            variables)
r             of relevant    (relevant
concepts      concepts)      variables
relating                     of
to the                       indicator
research                     s)
problem)
Househol       Level of     About the    About formal
                             45
ds                 income       savings        savings
purchasin         Expenditu     Forma         Saving
g power            re pattern     l               accounts
                  Savings        saving        Fix deposits
Objective         Family         s             NRFC
is,                supports      EPF
To                etc…          Jewelle      Or
examine                           ries          Rs.    Less
level   of                       etc…            than
household                                         100,000
s                                               Rs.
purchasin                                         100,000-
g power in                                        200,000
demandin
g a house
When the research design is completed, researcher can start
data collection and data analysis. The next sections present
some data analysis methods. This discussion is on quantitative
method, however, there are several methods tools that can be
used for qualitative analysis.
                                46
                        Chapter 03
        Real Estate Analysis-Quantitative Approach
Introduction to Quantitative Approach
After clearly understanding the research problem, it is possible
to formulate research objectives and hypotheses accordingly.
Finally, data collection and analysis to be done in order to
achieve the set objectives.
Branch of mathematics that deals with the analysis and
interpretation of numerical data in terms of samples and
populations are basically two types,
Descriptive Analysis
      Tables, Graphs, Summary Measures
Statistical Analysis (Statistical Inference)
       Estimation, Hypothesis Testing
Hypothesis Testing
Real Estate Researchers are also interested in answering many
types of questions. For example, a Property Developer might
want to know whether the land prices are going up and how. A
mortgagee (bank) might want to know whether a new property
tax will lower a mortgage loan disbursements. A Real Estate
                                 47
Sales Consultant might wish to see whether a new promotion
technique is better than a traditional one.
These types of questions can be addressed through statistical
hypothesis testing, which is a decision-making process for
evaluating claims about a population. In hypothesis testing, the
researcher must define the population under study, state the
particular hypotheses that will be investigated, give the
significance level, select a sample from the population, collect
the data, perform the calculations required for the statistical
test, and reach a conclusion.
Hypotheses concerning parameters such as means and
proportions can be investigated. There are two specific
statistical tests used for hypotheses concerning means: the z test
and the t test.
This chapter aims to explain basics in the hypothesis-testing
procedure along with the z test and the t test.
The three methods used to test hypotheses are;
1. The traditional method
2. The P-value method
3. The confidence interval method
The traditional method has been used since the hypothesis
testing method was formulated. A newer method, called the P-
value method, has become popular with the advent of modern
                                48
computers and high-powered statistical calculators. The third
method, the confidence interval method illustrates the
relationship between hypothesis testing and confidence
intervals.
Hypothesis Testing—Traditional Method
Every hypothesis-testing situation begins with the statement of
a hypothesis.
A statistical hypothesis is a conjecture about a population
parameter. This conjecture may or may not be true.
There are two types of statistical hypotheses for each situation:
the null hypothesis and the alternative hypothesis.
The null hypothesis, symbolized by H0, is a statistical
hypothesis that states that there is no difference between a
parameter and a specific value, or that there is no difference
between two parameters.
The alternative hypothesis, symbolized by H1, is a statistical
hypothesis that states the existence of a difference between a
parameter and a specific value, or states that there is a
difference between two parameters.
As an illustration of how hypotheses should be stated, three
different statistical studies will be used as examples.
                                49
Situation A: A Structural Engineer changes his drawing to
increase the physical life (durability) of a condominium.
If the mean life of the condominium without the structural
changes is 25 years, then his hypotheses are
H0: µ= 25 and H1: µ > 25
In this situation, the Structural Engineer is interested only in
increasing the lifetime of the condominium, so his alternative
hypothesis is that the mean is greater than 25 years. The null
hypothesis is that the mean is equal to 25 years. This test is
called right-tailed, since the interest is in an increase only.
Situation B A building facilities manager wishes to lower air
condition bills by using a special type of insulation in houses. If
the average of the monthly air condition bills is Rs 25,000, his
hypotheses about air condition costs with the use of insulation
are;
H0: µ= 25,000 and H1: µ < 25,000
This test is a left-tailed test, since the building facilities
manager is interested only in lowering air condition costs.
                                 50
Situation C: A Real Estate Researcher is interested in finding
out whether a new global economic downturn would have any
desirable effects on land sales. The researcher is particularly
concerned with the sales volume during the global economic
downturn. Will the sales volume increase, decrease, or remain
unchanged after a sales promotion?
Since the researcher knows that the land sales volume for the
Colombo District under study is Rs.100 million per month, the
hypotheses for this situation are;
H0: µ= 100 and H1: µ = 100
The null hypothesis specifies that the mean will remain
unchanged, and the alternative hypothesis states that it will be
different. This test is called a two-tailed test, since the possible
effects of the global economic downturn could be to raise or
lower the land sales volume.
To state hypotheses correctly, researchers must translate the
conjecture or claim from words into mathematical symbols.
The basic symbols used are as follows:
Equal to       =               Greater than     >
Not equal to   ≠               Less than        <
                                 51
The null and alternative hypotheses are stated together, and the
null hypothesis contains the equal sign, as shown (where k
represents a specified number).
Two-tailed test      Right-tailed          Left-tailed test
                     test
H0: µ= k             H0: µ= k              H0: µ= k
H1: µ ≠ k            H1: µ > k             H1: µ < k
When a researcher conducts a study, he or she is generally
looking for evidence to support a claim. Therefore, the claim
should be stated as the alternative hypothesis, i.e., using < or >
or =. Because of this, the alternative hypothesis is sometimes
called the research hypothesis.
A claim, though, can be stated as either the null hypothesis or
the alternative hypothesis; however, the statistical evidence can
only support the claim if it is the alternative hypothesis.
Statistical evidence can be used to reject the claim if the claim
is the null hypothesis.
Following table should be helpful in translating verbal
conjectures into mathematical symbols.
                                52
Hypothesis-Testing Common Phrases
               >                               <
is greater than                  is less than
is above                         is below
is higher than                    is lower than
is longer than                   is shorter than
is bigger than                   is smaller than
is increased                     is decreased or reduced from
              =                                  ≠
is equal to                      is not equal to
is the same as                   is different from
has not changed from             has changed from
is the same as                   is not the same as
Selection of an appropriate statistical test
Finally, the success or the failure of a research highly depend
on the selection of an appropriate statistical test. Hypotheses,
variables and nature of the data etc will be considered before
selecting a test.
Following diagrams guide researchers to select an appropriate
statistical test after considering objectives, hypotheses and
variables etc.
                               53
54
Correlation
In statistics, correlation is a technique which tells if two
variables are related or not and how much strong the
relationship. But this measure doesn’t indicate cause-effect
relation or impact of one on another.
Real Estate Developer wants to know whether there is a
relationship between land sales prices and distances to the town
centre. Accordingly data were collected on 200 land sales and
related distances to the town centre and tested for the normality.
Finally SPSS output of table generated with the data and tested
his research hypothesis.
                                55
Pearson Correlation - These numbers measure the strength
and direction of the linear relationship between the two
variables. The correlation coefficient can range from -1 to +1,
with -1 indicating a perfect negative correlation, +1 indicating a
perfect positive correlation, and 0 indicating no correlation at
all. (A variable correlated with itself will always have a
correlation coefficient of 1.)
From the scatterplot of the variables land perch price
and distance to town below, it is possible to see that the points
tend no pattern, which is the same as saying that the correlation
is weak negative. The -0.18 is the numerical description of how
tightly around the imaginary line the points lie.
If the correlation was higher, the points would tend to be closer
to the line; if it was smaller, they would tend to be further away
from the line. Also note that, by definition, any variable
correlated with itself has a correlation of 1.
Sig. (2-tailed) - This is the p-value associated with the
correlation.
                                56
N - This is number of cases that was used in the correlation.
Because data set has no missing data, all correlations were
based on all 200 cases in the data set. However, if some
variables had missing values, the N's would be different for the
different correlations.
                          Scatterplot
                               57
Linear Regression
 Linear Regression estimates the coefficients of the linear
 equation, involving one or more independent variables that
 best predict the value of the dependent variable. For example,
 it is possible to predict a land perch price (the dependent
 variable) from independent variables such as distance to town
 centre, extent, and frontage etc.
 Statistics. For each variable: number of valid cases, mean, and
 standard deviation. For each model: regression coefficients,
 correlation matrix, part and partial correlations, multiple R, R2,
 adjusted R2, change in R2, standard error of the estimate,
 analysis-of-variance table, predicted values, and residuals.
 Also, 95%-confidence intervals for each regression
 coefficient, variance-covariance matrix, variance inflation
 factor, tolerance, Durbin-Watson test, distance measures
 (Mahalanobis, Cook, and leverage values), DfBeta, DfFit,
 prediction intervals, and case wise diagnostics. Plots:
 scatterplots, partial plots, histograms, and normal probability
 plots.
 Data. The dependent and independent variables should be
 quantitative. Categorical variables, such as soil type, slope of
 the land, or area of land sale, need to be recoded to binary
 (dummy) variables or other types of contrast variables.
 Assumptions. For each value of the independent variable, the
 distribution of the dependent variable must be normal. The
                                 58
variance of the distribution of the dependent variable should
be constant for all values of the independent variable. The
relationship between the dependent variable and each
independent variable should be linear, and all observations
should be independent.
Regression Analysis: Land price Estimation Model
(Hedonic Model)
This case study shows an example regression analysis to
model the land price (dependent variable) subject to the
changes of distance to town, shape, extent, soil type etc
(independent variables) .These data were collected on 200 land
sales. SPSS 20. Package was used for the data analysis
purpose.
                              59
Model - SPSS allows to specify multiple models in a
single regression command. This indicates the number of the
model being reported.
Variables Entered – This indicates entered variables into a
regression in blocks, and it allows stepwise regression. Hence,
researchers need to know which variables were entered into the
current regression. If it doesn’t block the independent variables
or use stepwise regression, this column should list all of the
independent variables that the researcher specified.
Variables Removed - This column listed the variables that
were removed from the current regression. Usually, this
column will be empty unless the researcher did a stepwise
regression.
Method - This column shows the method that SPSS used to run
the regression. "Enter" means that each independent variable
was entered in usual fashion. If the researcher did a stepwise
regression, the entry in this column would show that.
Overall Model Fit
                                60
Model - SPSS allows to specify multiple models in a
single regression command. This indicates the number of the
model being reported.
R - R is the square root of R-Squared and is the correlation
between the observed and predicted values of dependent
variable.
R-Square - This is the proportion of variance in the dependent
variable (land perch price) which can be explained by the
independent variables (distance to town, shape, extent and soli
type etc). This is an overall measure of the strength of
association and does not reflect the extent to which any
particular independent variable is associated with the dependent
variable.
Adjusted R-square - This is an adjustment of the R-squared
that penalizes the addition of extraneous predictors to the
model. Adjusted R-squared is computed using the formula 1 -
((1 – R2) ((N - 1) / (N - k - 1)) where k is the number of
predictors.
Std. Error of the Estimate - This is also referred to as the root
mean squared error. It is the standard deviation of the error
term and the square root of the Mean Square for the Residuals
in the ANOVA table.
                                61
Model - SPSS allows to specify multiple models in a
single regression command. This indicates the number of the
model being reported.
Regression, Residual, Total - Looking at the breakdown of
variance in the outcome variable, these are the categories to be
examined: Regression, Residual, and Total. The Total variance
is partitioned into the variance which can be explained by the
independent variables (Model) and the variance which is not
explained by the independent variables (Error).
Sum of Squares - These are the Sum of Squares associated
with the three sources of variance, Total, Model and Residual.
The Total variance is partitioned into the variance which can be
explained by the independent variables (Regression) and the
variance which is not explained by the independent variables
(Residual).
df - These are the degrees of freedom associated with the
sources of variance. The total variance has N-1 degrees of
freedom. The Regression degrees of freedom corresponds to
                               62
the number of coefficients estimated minus 1. Including the
intercept, there are 11 coefficients, so the model has 11-1=10
degrees of freedom. The Error degrees of freedom is the DF
total minus the DF model, 151 - 10 =141.
Mean Square - These are the Mean Squares, the Sum of
Squares divided by their respective DF.
F and Sig. - This is the F-statistic the p-value associated with
it. The F-statistic is the Mean Square (Regression) divided by
the Mean Square (Residual): 11.654/1.072 = 10.86. The p-value
is compared to some alpha level in testing the null hypothesis
that all of the model coefficients are 0.
Variables in the model
Model - SPSS allows to specify multiple models in a
single regression command. This indicates the number of the
model being reported.
                               63
B - These are the values for the regression equation for
predicting the dependent variable from the independent
variable. The regression equation is presented in many different
ways, for example:
Y predicted = b0 + b1*x1 + b2*x2 + b3*x3 + b4*x4……+ e
The column of estimates provides the values for b0, b1, b2, b3…
and b10 for this equation.
Distance to town- The coefficient for Distance to town is
.837. So for every unit increase in Distance to town, a 0.837
thousand rupees increase in land perch price is predicted,
holding all other variables constant ( This positive impact will
be debatable).However it is possible to consider all other
coefficient values of independent variables.
 Std. Error - These are the standard errors associated with the
coefficients.
Beta - These are the standardized coefficients. These are the
coefficients that the researcher would obtain if the researcher
standardized all of the variables in the regression, including the
dependent and all of the independent variables, and ran the
regression. By standardizing the variables before running the
regression, researcher has to put all of the variables on the same
scale, and he can compare the magnitude of the coefficients to
see which one has more of an effect. The researcher will also
notice that the larger betas are associated with the larger t-
values and lower p-values.
                                64
t and Sig. - These are the t-statistics and their associated 2-
tailed p-values used in testing whether a given coefficient is
significantly different from zero. Using an alpha of 0.05: The
coefficient for Distance to town (0.837) is significantly
different from 0 because its p-value is 0.017, which is smaller
than 0.05.
 95% Confidence Limit for B Lower Bound and Upper
Bound - These are the 95% confidence intervals for the
coefficients. The confidence intervals are related to the p-
values such that the coefficient will not be statistically
significant if the confidence interval includes 0. These
confidence intervals can help the researcher to put the estimate
from the coefficient into perspective by seeing how much the
value could vary.
Discriminant Analysis
Discriminant analysis builds a predictive model for group
membership. The model is composed of a discriminant function
(or, for more than two groups, a set of discriminant functions)
based on linear combinations of the predictor variables that
provide the best discrimination between the groups. The
functions are generated from a sample of cases for which group
membership is known; the functions can then be applied to new
cases that have measurements for the predictor variables but
have unknown group membership.
                               65
Example. On average, people in rural areas think about the
possibility for more social interaction/ neighbourhood
relationships than people in the urban, and a greater proportion
of the people in the rural areas are farmers. A real estate
researcher wants to combine this information into a function to
determine how well an individual can discriminate between
the two groups of areas. The researcher thinks that population
size and economic information, social factors may also be
important.
Discriminant analysis allows him to estimate coefficients of
the linear discriminant function, which looks like the right side
of a multiple linear regression equation. That is, using
coefficients a, b, c, and d, the function is:
D = a * occupation + b * No of family members + c * level of
education + d * income per month
If these variables are useful for discriminating between the
two areas, the values of D will differ for the social interaction
and rural areas. If the researcher uses a stepwise variable
selection method, you may find that you do not need to
include all four variables in the function.
Statistics. For each variable: means, standard deviations,
univariate ANOVA. For each analysis: Box's M, within-
groups correlation matrix, within-groups covariance matrix,
separate-groups covariance matrix, total covariance matrix.
For each canonical discriminant function: eigenvalue,
                               66
 percentage of variance, canonical correlation, Wilks' lambda,
 chi-square. For each step: prior probabilities, Fisher's function
 coefficients, unstandardized function coefficients, Wilks'
 lambda for each canonical function.
 Data. The grouping variable must have a limited number of
 distinct categories, coded as integers. Independent variables
 that are nominal must be recoded to dummy or contrast
 variables.
 Assumptions. Cases should be independent. Predictor
 variables should have a multivariate normal distribution, and
 within-group variance-covariance matrices should be equal
 across groups. Group membership is assumed to be mutually
 exclusive (that is, no case belongs to more than one group) and
 collectively exhaustive (that is, all cases are members of a
 group). The procedure is most effective when group
 membership is a truly categorical variable; if group
 membership is based on values of a continuous variable (for
 example, high Land Price versus low Land Price), consider
 using linear regression to take advantage of the richer
 information that is offered by the continuous variable itself.
Logistic Regression
A Mortgage bank needs to know the loan repayment capacity of
its mortgage loan holding customers. Accordingly, data were
collected on 250 customers.
                                67
Loan repayment capacity is a dichotomous variable which has
Yes or No answer. Age, Income, Education, Employment and
other loans are the variables in the model.
This indicates about the cases that were included and excluded
from the analysis, the coding of the dependent variable, and
coding    of     any    categorical    variables   listed   on
the categorical subcommand.
 N - This is the number of cases in each category (e.g., included
in the analysis, missing, total).
Percent - This is the percent of cases in each category (e.g.,
included in the analysis, missing, total).
Included in Analysis - This row gives the number and percent
of cases that were included in the analysis. This has no missing
data in the data set, this also corresponds to the total number of
cases.
Missing Cases - This row give the number and percent of
missing cases. By default, SPSS logistic regression does a list
wise deletion of missing data. This means that if there is
                                68
missing value for any variable in the model, the entire case will
be excluded from the analysis.
Total - This is the sum of the cases that were included in the
analysis and the missing cases. In this example, 250 + 0 = 250
Block 0: Beginning Block
This part of the output describes a "null model", which is model
with no predictors and just the intercept. This is why you will
see all of the variables that you put into the model in the table
titled "Variables not in the Equation".
                                69
Step 0 - SPSS allows you to have different steps in your logistic
regression model. The difference between the steps is the
predictors that are included. This is similar to blocking
variables into groups and then entering them into the equation
one       group       at      a       time.      By     default,
SPSS logistic regression is run in two steps. The first step,
called Step 0, includes no predictors and just the intercept.
Often, this model is not interesting to researchers.
Observed - This indicates the number of 0's and 1's that are
observed in the dependent variable.
Predicted - In this null model, SPSS has predicted that all cases
are 0 on the dependent variable.
Overall Percentage - This gives the percent of cases for which
the dependent variables was correctly predicted given the
model. In this part of the output, this is the null model. 76.4 =
191/250.
B - This is the coefficient for the constant (also called the
"intercept") in the null model.
S.E. - This is the standard error around the coefficient for the
constant.
                                70
Wald and Sig. - This is the Wald chi-square test that tests the
null hypothesis that the constant equals 0. This hypothesis is
rejected because the p-value (listed in the column called "Sig.")
is smaller than the critical p-value of .05 (or .01). Hence, we
conclude that the constant is not 0. Usually, this finding is not
of interest to researchers.
df - This is the degrees of freedom for the Wald chi-square test.
There is only one degree of freedom because there is only one
predictor in the model, namely the constant.
Exp(B) - This is the exponentiation of the B coefficient, which
is an odds ratio. This value is given by default because odds
ratios can be easier to interpret than the coefficient, which is in
log-odds units. This is the odds: 59/191 = 0.3
Score and Sig. - This is a Score test that is used to predict
whether or not an independent variable would be significant in
the model. Looking at the p-values (located in the column
labelled "Sig.").
df - This column lists the degrees of freedom for each variable.
Each variable to be entered into the model, e.g., age, education,
income etc. has one degree of freedom, which leads to the total
of four shown at the bottom of the column.
Overall Statistics - This shows the result of including all of the
predictors into the model.
Block 1: Method = Enter
The section contains what is frequently the most interesting part
of the output: the overall test of the model (in the "Omnibus
                                 71
Tests of Model Coefficients" table) and the coefficients and
odds ratios (in the "Variables in the Equation" table).
                             72
Step 1 - This is the first step (or model) with predictors in it. In
this case, it is the full model that we specified in the logistic
regression command. You can have more steps if you do
stepwise or use blocking of variables.
Chi-square and Sig. - This is the chi-square statistic and its
significance level. In this example, the statistics for the Step,
Model and Block are the same because we have not used
stepwise logistic regression or blocking. The value given in the
Sig. column is the probability of obtaining the chi-square
statistic given that the null hypothesis is true. In other words,
this is the probability of obtaining this chi-square statistic
(37.635) if there is in fact no effect of the independent
variables, taken together, on the dependent variable. This is, of
course, the p-value, which is compared to a critical value,
perhaps .05 or .01 to determine if the overall model is
statistically significant. In this case, the model is statistically
significant because the p-value is less than .000.
df - This is the number of degrees of freedom for the model.
There is one degree of freedom for each predictor in the model.
In this example, we have five predictors: age, income,
education, employment and other loans
                                 73
-2 Log likelihood - This is the -2 log likelihood for the final
model. By itself, this number is not very informative.
However, it can be used to compare nested (reduced) models.
Cox & Snell R Square and Nagelkerke R Square - These are
pseudo R-squares. Logistic regression does not have an
equivalent to the R-squared that is found in OLS regression;
however, many people have tried to come up with one. There
are a wide variety of pseudo-R-square statistics (these are only
two of them). Because this statistic does not mean what R-
squared means in OLS regression (the proportion of variance
explained by the predictors).
Observed - This indicates the number of 0's and 1's that are
observed in the dependent variable.
Predicted - These are the predicted values of the dependent
variable based on the full logistic regression model. This table
shows how many cases are correctly predicted (184 cases are
observed to be No and are correctly predicted to be No; 50
cases are observed to be Yes and are correctly predicted to be
Yes), and how many cases are not correctly predicted (7 cases
are observed to be No but are predicted to be Yes; 9 cases are
observed to be Yes but are predicted to be No).
Overall Percentage - This gives the overall percent of cases
that are correctly predicted by the model. As you can see, this
percentage has increased from 76.4 for the null model to 77.2
for the full model.
B - These are the values for the logistic regression equation for
predicting the dependent variable from the independent
                                74
variable. They are in log-odds units.       Similar to OLS
regression, the prediction equation is
Log (p/1-p) = b0 + b1*x1 + b2*x2 + b3*x3 + b3*x3+b4*x4
Where p is the probability of being loan payable. Expressed in
terms of the variables used in this example, the logistic
regression equation is
Log (p/1-p) = 0.02 + -0.03*age + 0.24*income – 0.412
education - 0.257* employment + 0.154 other loans
                              75
Factor Analysis
 In a questionnaire, several questions might be included to
 measure one factor. For example, 5 questions can be asked
 from respondents to verify his/her perception on impact of
 2008- economic crisis on real estate property market in Sri
 Lanka. However, all five (05) questions direct to measure one
 factor “impact of 2008- economic crisis on real estate property
 market”.
 Factor analysis attempts to identify underlying variables, or
 factors, that explain the pattern of correlations within a set of
 observed variables. Factor analysis is often used in data
 reduction to identify a small number of factors that explain
 most of the variance that is observed in a much larger number
 of manifest variables. Factor analysis can also be used to
 generate hypotheses regarding causal mechanisms or to screen
 variables for subsequent analysis (for example, to identify
 collinearity prior to performing a linear regression analysis).
 The factor analysis procedure offers a high degree of
 flexibility:
  • Seven methods of factor extraction are available.
  • Five methods of rotation are available, including direct
     oblimin and promax for nonorthogonal rotations.
                                76
 • Three methods of computing factor scores are available,
    and scores can be saved as variables for further analysis.
Example. What underlying attitudes lead people to respond to
the questions on a real estate market related survey as they do?
Examining the correlations among the survey items reveals
that there is significant overlap among various subgroups of
items--questions about property taxes tend to correlate with
each other, questions about property ownership issues
correlate with each other, and so on.
With factor analysis, you can investigate the number of
underlying factors and, in many cases, identify what the
factors represent conceptually. Additionally, you can compute
factor scores for each respondent, which can then be used in
subsequent analyses. For example, you might build a logistic
regression model to predict voting behavior based on factor
scores.
Statistics. For each variable: number of valid cases, mean, and
standard deviation. For each factor analysis: correlation matrix
of variables, including significance levels, determinant, and
inverse; reproduced correlation matrix, including anti-image;
initial solution (communalities, eigenvalues, and percentage of
variance explained); Kaiser-Meyer-Olkin measure of sampling
adequacy and Bartlett's test of sphericity; unrotated solution,
including factor loadings, communalities, and eigenvalues;
and rotated solution, including rotated pattern matrix and
                               77
 transformation matrix. For oblique rotations: rotated pattern
 and structure matrices; factor score coefficient matrix and
 factor covariance matrix. Plots: scree plot of eigenvalues and
 loading plot of first two or three factors.
Data. The variables should be quantitative at the interval or
ratio level. Categorical data (such as education level or
property type) are not suitable for factor analysis. Data for
which Pearson correlation coefficients can sensibly be
calculated should be suitable for factor analysis.
Assumptions. The data should have a bivariate normal
distribution for each pair of variables, and observations should
be independent. The factor analysis model specifies that
variables are determined by common factors (the factors
estimated by the model) and unique factors (which do not
overlap between observed variables); the computed estimates
are based on the assumption that all unique factors are
uncorrelated with each other and with the common factors.
In this example we have included many options, including the
scree plot and the plot of the rotated factors. While you may
not wish to use all of these options, we have included them here
to aid in the explanation of the analysis. We have also created a
page of annotated output for a principal components analysis
that parallels this analysis.
                                78
Mean - These are the means of the variables used in the factor
analysis.
Std. Deviation - These are the standard deviations of the
variables used in the factor analysis.
Analysis N - This is the number of cases used in the factor
analysis.
                              79
Kaiser-Meyer-Olkin Measure of Sampling Adequacy - This
measure varies between 0 and 1, and values closer to 1 are
better. A value of .6 is a suggested minimum.
Bartlett's Test of Sphericity - This tests the null hypothesis
that the correlation matrix is an identity matrix. An identity
matrix is matrix in which all of the diagonal elements are 1 and
all off diagonal elements are 0. You want to reject this null
hypothesis.
Taken together, these tests provide a minimum standard which
should be passed before a factor analysis (or a principal
components analysis) should be conducted.
Communalities - This is the proportion of each variable's
variance that can be explained by the factors (e.g., the
                               80
underlying latent continua). It is also noted as h2 and can be
defined as the sum of squared factor loadings for the variables.
Initial - With principal factor axis factoring, the initial values
on the diagonal of the correlation matrix are determined by the
squared multiple correlation of the variable with the other
variables.
Extraction - The values in this column indicate the proportion
of each variable's variance that can be explained by the retained
factors. Variables with high values are well represented in the
common factor space, while variables with low values are not
well represented. (In this example, we don't have any
particularly low values.) They are the reproduced variances
from the factors that you have extracted. You can find these
values on the diagonal of the reproduced correlation matrix.
Factor - The initial number of factors is the same as the number
of variables used in the factor analysis. However, not all 7
factors will be retained. In this example, only the first two
factors will be retained.
Initial Eigenvalues - Eigenvalues are the variances of the
factors. Because we conducted our factor analysis on the
                                81
correlation matrix, the variables are standardized, which means
that the each variable has a variance of 1, and the total variance
is equal to the number of variables used in the analysis, in this
case, 7.
Total - This column contains the eigenvalues. The first factor
will always account for the most variance (and hence have the
highest eigenvalue), and the next factor will account for as
much of the left over variance as it can, and so on. Hence, each
successive factor will account for less and less variance.
% of Variance - This column contains the percent of total
variance accounted for by each factor.
Cumulative % - This column contains the cumulative
percentage of variance accounted for by the current and all
preceding factors. For example, the second row shows a value
of 71.81. This means that the first two factors together account
for 71.81% of the total variance.
Extraction Sums of Squared Loadings - The number of rows
in this panel of the table correspond to the number of factors
retained. In this example, we requested that two factors be
retained, so there are two rows, one for each retained factor.
The values in this panel of the table are calculated in the same
way as the values in the left panel, except that here the values
are based on the common variance. The values in this panel of
the table will always be lower than the values in the left panel
of the table, because they are based on the common variance,
which is always smaller than the total variance.
                                82
Rotation Sums of Squared Loadings - The values in this
panel of the table represent the distribution of the variance after
the varimax rotation. Varimax rotation tries to maximize the
variance of each of the factors, so the total amount of variance
accounted for is redistributed over the three extracted factors.
The scree plot graphs the eigenvalue against the factor number.
You can see these values in the first two columns of the table
immediately above. From the third factor on, you can see that
the line is almost flat, meaning the each successive factor is
                                 83
accounting for smaller and smaller amounts of the total
variance.
Rotated Factor Matrix - This table contains the rotated factor
loadings (factor pattern matrix), which represent both how the
variables are weighted for each f actor but also the correlation
between the variables and the factor. Because these are
correlations, possible values range from -1 to +1.
For orthogonal rotations, such as varimax, the factor pattern and
factor structure matrices are the same.
Factor - The columns under this heading are the rotated factors
that have been extracted. These are the factors that analysts are
most interested in and try to name.
                                84
Factor Transformation Matrix - This is the matrix by which
you multiply the unrotated factor matrix to get the rotated factor
matrix.
                                85
The plot above shows the items (variables) in the rotated factor
space. While this picture may be particularly helpful, when you
get this graph in the SPSS output, you can interactively rotate
it. This may help you to see how the items (variables) are
organized in the common factor space. Accordingly Shape is
slightly away from the other factors.
                               86
                        Chapter 04
        Real Estate Analysis- Validity and Reliability
As real estate researches and studies are a part of the social
science researches, the estimation of reliability and validity are
tasks frequently encountered.
Measurement issues differ in the social sciences in that they are
related to the quantification of abstract, intangible and
unobservable constructs. In many instances, then, the meaning
of quantities is only inferred.
Most concepts in the behavioural sciences have meaning within
the context of the theory that they are a part of. Each concept,
thus, has an operational definition which is governed by the
central theory. If a concept is involved in the testing of
hypothesis to support the theory it has to be measured. So the
first decision that the research is faced with is “how the concept
shall be measured?” That is the type of measure. At a very
broad level the type of measure can be observational, self-
report, interview, etc. These types ultimately take shape of a
more specific form like observation of ongoing activity,
observing video-taped events, self-report measures like
questionnaires that can be open-ended or close-ended, Likert-
type scales, interviews that are structured, semi-structured or
unstructured and open-ended or close-ended.
                                87
Each type of measure has specific types of issues that need to
be addressed to make the measurement meaningful, accurate,
and efficient.
        Another important feature is the population for which
the measure is intended. This decision is not entirely dependent
on the theoretical paradigm but more to the immediate research
question at hand.
       A third point that needs mentioning is the purpose of the
scale or measure. What is it that the researcher wants to do
with the measure? Is it developed for a specific study or is it
developed with the anticipation of extensive use with similar
populations?
        Once some of these decisions are made and a measure is
developed, which is a careful and tedious process, the relevant
questions to raise are “how do we know that we are indeed
measuring what we want to measure?” since the construct that
we are measuring is abstract, and “can we be sure that if we
repeated the measurement we will get the same result?”. The
first question is related to validity and second to reliability.
Validity and reliability are two important characteristics of
behavioural measure and are referred to as psychometric
properties.
                               88
        It is important to bear in mind that validity and
reliability are not an all or none issue but a matter of
degree.
Validity of Research Outcomes
        Very simply, validity is the extent to which a test
measures what it is supposed to measure. The question of
validity is raised in the context of the three points made above,
the form of the test, the purpose of the test and the population
for whom it is intended. Therefore, it is not possible to ask the
general question “Is this a valid test?” The question to ask is
“how valid is this test for the decision that I need to make?” or
“how valid is the interpretation I propose for the test?” It is
possible divide the types of validity into logical and empirical.
Content Validity:
        When researcher wants to find out if the entire content
of the behaviour/construct/area is represented in the test we
compare the test task with the content of the behaviour. This is
a logical method, not an empirical one.
         Example, if researcher wants to analyse buying
behaviour of Sri Lankan residential property buyers, it is not
fair/ possible to use questions/test perception aspects in
literature or instruments used in European countries; Sri Lankan
context is more or less different from European or others.
                                89
Face Validity:
       Basically face validity refers to the degree to which a
test appears to measure what it purports to measure.
Researchers need to maintain/understand the link among
research problem, objective/s, hypothesis and statistical test/s
properly.
Criterion-Oriented or Predictive Validity:
        When a researcher is expecting a future land sales based
on the land sales records obtained currently by the measure,
correlate the sales records obtained with the future sales. The
future land sales is called the criterion and the current land sales
records is the prediction. This is an empirical check on the
value of the test – a criterion-oriented or predictive validation.
Concurrent Validity:
        An example in Real Estate Studies, Concurrent validity
is the degree to which the records on a land sale are related to
the records on another, already established, sale occurred at the
same time, or to some other valid criterion available at the same
time. Logically, predictive and concurrent validation are the
same, the term concurrent validation is used to indicate that no
time elapsed between measures.
Construct Validity:
       Construct validity is the degree to which a test measures
an intended hypothetical construct. Many times psychologists
assess/measure abstract attributes or constructs. The process of
                                 90
validating the interpretations about that construct as indicated
by the test score is construct validation.
Reliability of Research Outcomes
       Every Research requires dependable measurement.
Measurements are reliable to the extent that they are repeatable
and that any random influence which tends to make
measurements different from occasion to occasion or
circumstance to circumstance is a source of measurement error.
        Reliability is the degree to which a test consistently
measures whatever it measures. Errors of measurement that
affect reliability are random errors and errors of measurement
that affect validity are systematic or constant errors.
Reliability Analysis
 Reliability analysis allows you to study the properties of
 measurement scales and the items that compose the scales.
 The Reliability Analysis procedure calculates a number of
 commonly used measures of scale reliability and also provides
 information about the relationships between individual items
 in the scale. Intra class correlation coefficients can be used to
 compute inter-rater reliability estimates.
 Example. Does my questionnaire measure customer
 satisfaction in a useful way? Using reliability analysis, you can
 determine the extent to which the items in your questionnaire
                                91
are related to each other, you can get an overall index of the
repeatability or internal consistency of the scale as a whole,
and you can identify problem items that should be excluded
from the scale.
Statistics. Descriptive for each variable and for the scale,
summary statistics across items, inter-item correlations and
covariance, reliability estimates, ANOVA table, intra-class
correlation coefficients, Hotelling's T2, and Tukey's test of
additivity.
Models. The following models of reliability are available:
 • Alpha (Cronbach). This model is a model of internal
    consistency, based on the average inter-item correlation.
 • Split-half. This model splits the scale into two parts and
    examines the correlation between the parts.
 • Guttman. This model computes Guttman's lower bounds
    for true reliability.
 • Parallel. This model assumes that all items have equal
    variances and equal error variances across replications.
 • Strict parallel. This model makes the assumptions of the
    Parallel model and also assumes equal means across
    items.
                              92
 Data. Data can be dichotomous, ordinal, or interval, but the
 data should be coded numerically.
 Assumptions. Observations should be independent, and errors
 should be uncorrelated between items. Each pair of items
 should have a bivariate normal distribution. Scales should be
 additive, so that each item is linearly related to the total score.
 Related procedures. If you want to explore the
 dimensionality of your scale items (to see whether more than
 one construct is needed to account for the pattern of item
 scores), use factor analysis or multidimensional scaling. To
 identify homogeneous groups of variables, use hierarchical
 cluster analysis to cluster variables.
        Test-retest, equivalent forms and split-half reliability are
all determined through correlation.
Test-retest Reliability:
        Test-retest reliability is the degree to which
outcomes/results are consistent over time.          It indicates
outcomes/results       variation     that      occurs       from
surveying/investigation to surveying/investigation as a result of
errors of measurement.
Split-Half Reliability:
       Requires only one administration.         Especially
appropriate when the test is very long. The most commonly
                                 93
used method to split the test into two is using the odd-even
strategy. Since longer tests tend to be more reliable, and since
split-half reliability represents the reliability of a test only half
as long as the actual test, a correction formula must be applied
to the coefficient. Spearman-Brown prophecy formula.
         Split-half reliability is a form of internal consistency
reliability.
Internal Consistency Reliability:
        Determining how all items on the test relate to all other
items. Kudser-Richardson is an estimate of reliability that is
essentially equivalent to the average of the split-half reliabilities
computed for all possible halves.
In a research, for every dimension of interest and specific
question or set of questions, there are a vast number of ways to
make questions. Although the guiding principle should be the
specific purposes of the research, there are better and worse
questions for any particular operationalization. How to evaluate
the measures?
        Two of the primary criteria of evaluation in any
measurement or observation are:
       Whether we are measuring what we intend to measure.
       Whether the same measurement process yields the same
              results.
        These two concepts are validity and reliability.
                                  94
Reliability is concerned with questions of stability and
consistency - does the same measurement tool yield stable and
consistent results when repeated over time.
Example: To calculate the extent of a piece of land, a tape
measure is a highly reliable measuring instrument. If the extent
of the land is 12 perches. You measure it once with the tape
measure - you get an extent 12 perches. Measure it again and
you get 12 perches. Measure it repeatedly and you consistently
get a measurement 12 perches. The tape measure yields reliable
results.
Validity refers to the extent we are measuring what we hope to
measure (and what we think we are measuring). To find out the
extent of a piece of land , a measuring tape that has been
created with accurate spacing for inches, feet, etc. should yield
valid results as well. Measuring this piece of land with a "good"
measuring tape should produce a correct measurement of the
land extent.
        These concepts are applicable in social research, we
want to use measurement tools that are both reliable and valid.
We want questions that yield consistent responses when asked
multiple times - this is reliability. Similarly, we want questions
that get accurate responses from respondents - this is validity
                                95
Validity and Reliability Convergence
Source: Kendell, R; Jablensky, A (2003).
                               96
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                               97
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Glossary
Adjusted R2 used in multiple regression when n and k are
approximately equal, to provide a more realistic value of R2
Alpha the probability of a type I error, represented by the
Greek letter a
Alternative hypothesis a statistical hypothesis that states
difference between a parameter and a specific value or states
that there is a difference between two parameters
Analysis of variance (ANOVA) a statistical technique used to
test a hypothesis concerning the means of three or more
populations
ANOVA summary table the table used to summarize the
results of an ANOVA test
Bayes’ theorem a theorem that allows you to compute the
revised probability of an event that occurred before another
event when the events are dependent
Beta the probability of a type II error, represented by the Greek
letter b
Between-group variance a variance estimate using the means
of the groups or between the groups in an F test
                                99
Biased sample a sample for which some type of systematic
error has been made in the selection of subjects for the sample
Bimodal a data set with two modes
Binomial distribution the outcomes of a binomial experiment
and the corresponding probabilities of these outcomes
Binomial experiment a probability experiment in which each
trial has only two outcomes, there are a fixed number of trials,
the outcomes of the trials are Independent, and the probability
of success remains the same for each trial
Boxplot a graph used to represent a data set when the dataset
contains a small number of values
Categorical frequency distribution a frequency distribution
used when the data are categorical (nominal)
Central limit theorem a theorem that states that as the sample
size increases, the shape of the distribution of the sample means
taken from the population with mean m and standard deviation
s will approach a normal distribution; the distribution will have
a mean m and a standard deviation
Chebyshev’s theorem a theorem that states that the proportion
of values from a data set that fall within k standard deviations of
                                100
the mean will be at least1 _ 1_k2, where k is a number greater
than 1
Chi-square distribution a probability distribution obtained
from the values of (n _ 1) s2_s2 when random samples are
selected from a normally distributed population whose variance
is s2
Class boundaries the upper and lower values of a class for A
grouped frequency distribution whose values have one
Additional decimal place more than the data and end in The
digit 5
Class midpoint a value for a class in a frequency Distribution
obtained by adding the lower and upper Class boundaries (or
the lower and upper class limits) And dividing by 2
Class width the difference between the upper class Boundary
and the lower class boundary for a class in a Frequency
distribution
Classical probability the type of probability that uses Sample
spaces to determine the numerical probability that an event will
happen
Cluster sample a sample obtained by selecting a Preexisting or
natural group, called a cluster, and using the members in the
cluster for the sample
                               101
Coefficient of determination a measure of the variation of the
dependent variable that is explained by the Regression line and
the independent variable; the ratio of the explained variation to
the total variation
Coefficient of variation the standard deviation divided by
The mean; the result is expressed as a percentage
Combination a selection of objects without regard to order
Complement of an event the set of outcomes in the sample
Space that are not among the outcomes of the event itself
Compound event an event that consists of two or more
Outcomes or simple events
Conditional probability the probability that an event B Occurs
after an event A has already occurred
Confidence interval a specific interval estimate of a Parameter
determined by using data obtained from a Sample and the
specific confidence level of the estimate
Confidence level the probability that a parameter lies within
the specified interval estimate of the parameter
                               102
Confounding variable a variable that influences the Outcome
variable but cannot be separated from the other Variables that
influence the outcome variable
Consistent estimator an estimator whose value approaches
The value of the parameter estimated as the sample size
Increases
Contingency table data arranged in table form for the chi-
square Independence test, with R rows and C columns
Continuous variable a variable that can assume all values
Between any two specific values; a variable obtained by
measuring
Control group a group in an experimental study that is not
given any special treatment
Convenience sample sample of subjects used because they
Are convenient and available
Correction for continuity a correction employed when a
Continuous distribution is used to approximate a discrete
distribution
Correlation a statistical method used to determine whether a
linear relationship exists between variables
                              103
Correlation coefficient a statistic or parameter that measures
the strength and direction of a linear Relationship between two
variables
Critical or rejection region the range of values of the test
Value that indicates that there is a significant difference and the
null hypothesis should be rejected in a Hypothesis test
Critical value (C.V.) a value that separates the critical Region
from the noncritical region in a hypothesis test
Cumulative frequency the sum of the frequencies
Accumulated up to the upper boundary of a class in a
Frequency distribution
Data measurements or observations for a variable
Data array a data set that has been ordered
Data set a collection of data values
Data value or datum a value in a data set
Decile a location measure of a data value; it divides the
Distribution into 10 groups
                                104
Degrees of freedom the number of values that are free to Vary
after a sample statistic has been computed; used when a
distribution (such as the t distribution) consists Of a family of
curves
Dependent events events for which the outcome or Occurrence
of the first event affects the outcome or Occurrence of the
second event in such a way that the Probability is changed
Dependent samples samples in which the subjects are Paired
or matched in some way; i.e., the samples are Related
Dependent variable a variable in correlation and Regression
analysis that cannot be controlled or manipulated
Descriptive statistics a branch of statistics that consists of the
collection, organization, summarization, and Presentation of
data
Discrete variable a variable that assumes values that can be
counted
Disordinal interaction an interaction between variables In
ANOVA, indicated when the graphs of the lines Connecting the
mean intersect
Distribution-free statistics see nonparametric statistics
                                105
Double sampling a sampling method in which a Very large
population is given a questionnaire to determine those who
meet the qualifications for a Study; the questionnaire is
reviewed, a second smaller Population is defined, and a sample
is selected from this group
Empirical probability the type of probability that uses
Frequency distributions based on observations to determine
numerical probabilities of events
Empirical rule a rule that states that when a distribution is
Bell-shaped (normal), approximately 68% of the data Values
will fall within 1 standard deviation of the mean;
Approximately 95% of the data values will fall within 2
standard deviations of the mean; and approximately 99.7% of
the data values will fall within 3 standard Deviations of the
mean
Equally likely events the events in the sample space that Have
the same probability of occurring
Estimation the process of estimating the value of a Parameter
from information obtained from a sample
Estimator a statistic used to estimate a parameter
Event outcome of a probability experiment
                               106
Expected frequency the frequency obtained by calculation (as
if there were no preference) and used in the chi-square Test
Expected value the theoretical average of a variable that has
A probability distribution
Experimental study a study in which the researcher
manipulates one of the variables and tries to determine how the
manipulation influences other variables
Explanatory variable a variable that is being manipulated by
the researcher to see if it affects the outcome variable
Exploratory data analysis the act of analyzing data to
determine what information can be obtained by using Stem and
leaf plots, medians, interquartile ranges, and Boxplots
Extrapolation use of the equation for the regression line to
Predict y_ for a value of x which is beyond the range of the data
values of x
F distribution the sampling distribution of the Variances when
two independent samples are selected from two normally
distributed populations in which the Variances are equal and the
variances and are compared as _
F test a statistical test used to compare two variances or three
or more means
                               107
Factors the independent variables in ANOVA tests
Finite population correction factor a correction factor Used to
correct the standard error of the mean when the Sample size is
greater than 5% of the population size
Five-number summary five specific values for a data set That
consist of the lowest and highest values, Q1 and Q3, And the
median
Frequency the number of values in a specific class of a
Frequency distribution
Frequency distribution an organization of raw data in Table
form, using classes and frequencies
Frequency polygon a graph that displays the data by using
Lines that connect points plotted for the frequencies at the
midpoints of the classes
Goodness-of-fit test a chi-square test used to see whether a
Frequency distribution fits a specific pattern
Grouped frequency distribution a distribution used when the
range is large and classes of several units in width are needed
                              108
Hawthorne effect an effect on an outcome variable caused by
the fact that subjects of the study know that they are
participating in the study
Histogram a graph that displays the data by using vertical Bars
of various heights to represent the frequencies of a distribution
Homogeneity of proportions test a test used to determine
The equality of three or more proportions
Hypergeometric distribution the distribution of a variable that
has two outcomes when sampling is done without Replacement
Hypothesis testing a decision-making process for Evaluating
claims about a population
Independence test a chi-square test used to test the
Independence of two variables when data are tabulated In table
form in terms of frequencies
Independent events events for which the probability of the
First occurring does not affect the probability of the Second
occurring
Independent samples samples that are not related
Independent variable a variable in correlation and Regression
analysis that can be controlled or manipulated
                               109
Inferential statistics a branch of statistics that consists of
Generalizing from samples to populations, performing
Hypothesis testing, determining relationships among Variables,
and making predictions
Influential observation an observation which when Removed
from the data values would markedly change the position of the
regression line
Interaction effect the effect of two or more variables on Each
other in a two-way ANOVA study
Interquartile range Q3 _ Q1
Interval estimate a range of values used to estimate a
Parameter
Interval level of measurement a measurement level that Ranks
data and in which precise differences between Units of measure
exist. See also nominal, ordinal, and Ratio levels of
measurement
Kruskal-Wallis test a nonparametric test used to compare three
or more means
Law of large numbers when a probability experiment is
repeated a large number of times, the relative frequency
                              110
Probability of an outcome will approach its theoretical
Probability
Least-squares line another name for the regression line
Left-tailed test a test used on a hypothesis when the critical
Region is on the left side of the distribution
Level a treatment in ANOVA for a variable
Level of significance the maximum probability of committing a
type I error in hypothesis testing
Lower class limit the lower value of a class in a frequency
Distribution that has the same decimal place value as the data
Lurking variable a variable that influences the relationship
Between x and y, but was not considered in the study
Main effect the effect of the factors or independent Variables
when there is a nonsignificant interaction effect in a two-way
ANOVA study
Marginal change the magnitude of the change in the
Dependent variable when the independent variable Changes 1
unit
                              111
Maximum error of estimate the maximum likely Difference
between the point estimate of a parameter and the actual value
of the parameter
Mean the sum of the values, divided by the total number of
values
Mean square the variance found by dividing the sum of the
squares of a variable by the corresponding degrees Of freedom;
used in ANOVA
Measurement scales a type of classification that tells how
variables are categorized, counted, or measured; the four types
of scales are nominal, ordinal, interval, and ratio
Median the midpoint of a data array
Midrange the sum of the lowest and highest data values,
Divided by 2
Modal class the class with the largest frequency
Mode the value that occurs most often in a data set
Monte Carlo method a simulation technique using Random
numbers
Multimodal a data set with three or more modes
                               112
Multinomial distribution a probability distribution for an
Experiment in which each trial has more than two Outcomes
Multiple correlation coefficient a measure of the strength of
the relationship between the independent variables And the
dependent variable in a multiple regression study
Multiple regression a study that seeks to determine if several
independent variables are related to a dependent Variable
Multiple relationship a relationship in which many Variables
are under study
Multistage sampling a sampling technique that uses a
Combination of sampling methods
Mutually exclusive events probability events that cannot occur
at the same time
Negative relationship a relationship between variables Such
that as one variable increases, the other variable Decreases, and
vice versa
Negatively skewed or left-skewed distribution a Distribution
in which the majority of the data values fall to the right of the
mean
                               113
Nominal level of measurement a measurement level that
Classifies data into mutually exclusive (no overlapping)
Exhaustive categories in which no order or ranking can be
imposed on them. See also interval, ordinal, and ratio Levels of
measurement
Noncritical or no rejection region the range of values of the
test value that indicates that the difference was probably due to
chance and the null hypothesis should not be rejected
Nonparametric statistics a branch of statistics for use when
the population from which the samples are selected is not
normally distributed and for use in testing Hypotheses that do
not involve specific population Parameters
No rejection region see noncritical region
Normal distribution a continuous, symmetric, bell-shaped
Distribution of a variable
Normal quantile plot graphical plot used to determine whether
a variable is approximately normally distributed
Null hypothesis a statistical hypothesis that states that there is
no difference between a parameter and a specific Value or that
there is no difference between two Parameters
                                114
Observational study a study in which the researcher merely
observes what is happening or what has happened in the past
and draws conclusions based on these observations
Observed frequency the actual frequency value obtained from
a sample and used in the chi-square test
Ogive a graph that represents the cumulative frequencies for the
classes in a frequency distribution
One-tailed test a test that indicates that the null hypothesis
should be rejected when the test statistic value is in the Critical
region on one side of the mean
One-way ANOVA a study used to test for differences among
means for a single independent variable when there are three or
more groups
Open-ended distribution a frequency distribution that has No
specific beginning value or no specific ending value
Ordinal interaction an interaction between variables in
ANOVA, indicated when the graphs of the lines connecting the
means do not intersect
Ordinal level of measurement a measurement level that
Classifies data into categories that can be ranked; however,
                                115
precise differences between the ranks do not exist. See also
interval, nominal, and ratio levels of Measurement
Outcome the result of a single trial of a probability Experiment
Outcome variable a variable that is studied to see if it has
changed significantly due to the manipulation of the
Explanatory variable
Outlier an extreme value in a data set; it is omitted from a
Boxplot
Parameter a characteristic or measure obtained by using all the
data values for a specific population
Parametric tests statistical tests for population parameters
Such as means, variances, and proportions that involve
Assumptions about the populations from which the Samples
were selected
Pareto chart chart that uses vertical bars to represent
Frequencies for a categorical variable
Pearson product moment correlation coefficient (PPMCC) a
statistic used to determine the strength of a Relationship when
the variables are normally distributed
Pearson’s index of skewness value used to determine the
Degree of skewness of a variable
                               116
Percentile a location measure of a data value; it divides the
Distribution into 100 groups
Permutation an arrangement of n objects in a specific order
Pie graph a circle that is divided into sections or wedges
According to the percentage of frequencies in each Category of
the distribution
Point estimate a specific numerical value estimate of a
Parameter
Poisson distribution a probability distribution used when N is
large and p is small and when the independent Variables occur
over a period of time
Pooled estimate of the variance a weighted average of the
variance using the two sample variances and their Respective
degrees of freedom as the weights
Population the totality of all subjects possessing certain
Common characteristics that are being studied
Population correlation coefficient the value of the Correlation
coefficient computed by using all possible Pairs of data values
(x, y) taken from a population
                              117
Positive relationship a relationship between two variables
Such that as one variable increases, the other variable Increases
or as one variable decreases, the other Decreases
Positively skewed or right-skewed distribution a distribution
in which the majority of the data values fall to the left of the
mean
Power of a test the probability of rejecting the null Hypothesis
when it is false
Prediction interval a confidence interval for a predicted Value
y
Probability the chance of an event occurring
Probability distribution the values a random variable can
assume and the corresponding probabilities of the values
Probability experiment a chance process that leads to Well-
defined results called outcomes
Proportion a part of a whole, represented by a fraction, a
Decimal, or a percentage
P-value the actual probability of getting the sample mean Value
if the null hypothesis is true
                               118
Qualitative variable a variable that can be placed into Distinct
categories, according to some characteristic or Attribute
Quantiles values that separate the data set into approximately
equal groups
Quantitative variable a variable that is numerical in nature and
that can be ordered or ranked
Quartile a location measure of a data value; it divides the
Distribution into four groups
Quasi-experimental study a study that uses intact groups
Rather than random assignment of subjects to groups
Random sample a sample obtained by using random or Chance
methods; a sample for which every member of the population
has an equal chance of being selected
Random variable a variable whose values are determined by
chance
Range the highest data value minus the lowest data value
Range rule of thumb dividing the range by 4, given an
Approximation of the standard deviation
Ranking the positioning of a data value in a data array
According to some rating scale
                               119
Ratio level of measurement a measurement level that
possesses all the characteristics of interval measurement and a
true zero; it also has true ratios between different Units of
measure. See also interval, nominal, and ordinal Levels of
measurement
Raw data data collected in original form
Regression a statistical method used to describe the Nature of
the relationship between variables, that Is, a positive or
negative, linear or nonlinear Relationship
Regression line the line of best fit of the data
Rejection region see critical region
Relative frequency graph a graph using proportions Instead of
raw data as frequencies
Relatively efficient estimator an estimator that has the
smallest variance from among all the statistics that can be used
to estimate a parameter
Residual the difference between the actual value of y and the
predicted value y_ for a specific value of x
Resistant statistic a statistic that is not affected by an
extremely skewed distribution
                                 120
Right-tailed test a test used on a hypothesis when the Critical
region is on the right side of the distribution
Run a succession of identical letters preceded by or Followed
by a different letter or no letter at all, such as the beginning or
end of the succession
Runs test a nonparametric test used to determine whether
Data are random
Sample a group of subjects selected from the population
Sample space the set of all possible outcomes of a Probability
experiment
Sampling distribution of sample means a distribution
Obtained by using the means computed from random Samples
taken from a population
Sampling error the difference between the sample measure
and the corresponding population measure due to the Fact that
the sample is not a perfect representation of the Population
Scatter plot a graph of the independent and dependent
Variables in regression and correlation analysis
Scheffé test a test used after ANOVA, if the null hypothesis s
rejected, to locate significant differences in the means
                                121
Sequence sampling a sampling technique used in quality
Control in which successive units are taken from Production
lines and tested to see whether they meet the Standards set by
the manufacturing company
Sign test a nonparametric test used to test the value of the
Median for a specific sample or to test sample means in A
comparison of two dependent samples
Simple event an outcome that results from a single trial of A
probability experiment
Simple relationship a relationship in which only two Variables
are under study
Simulation techniques techniques that use            probability
Experiments to mimic real-life situations
Spearman rank correlation coefficient the nonparametric
Equivalent to the correlation coefficient, used when the data are
ranked
Standard deviation the square root of the variance
Standard error of the estimate the standard deviation of the
observed y values about the predicted y values in Regression
and correlation analysis
                               122
Standard error of the mean the standard deviation of the
Sample means for samples taken from the same Population
Standard normal distribution a normal distribution for which
the mean is equal to 0 and the standard deviation is equal to 1
Standard score the difference between a data value and the
Mean, divided by the standard deviation
Statistic a characteristic or measure obtained by using the Data
values from a sample
Statistical hypothesis a conjecture about a population
Parameter, which may or may not be true
Statistical test a test that uses data obtained from a sample to
make a decision about whether the null hypothesis should be
rejected
Statistics the science of conducting studies to collect, Organize,
summarize, analyze, and draw conclusions from data
Stem and leaf plot a data plot that uses part of a data value as
the stem and part of the data value as the leaf to form Groups or
classes
Stratified sample a sample obtained by dividing the Population
into subgroups, called strata, according to Various
                                123
homogeneous characteristics and then selecting Members from
each stratum
Subjective probability the type of probability that uses a
probability value based on an educated guess Or estimate,
employing opinions and inexact Information
Sum of squares between groups a statistic computed in the
numerator of the fraction used to find the between group
Variance in ANOVA
Sum of squares within groups a statistic computed in the
Numerator of the fraction used to find the within-group
Variance in ANOVA
Symmetric distribution a distribution in which the data Values
are uniformly distributed about the mean
Systematic sample a sample obtained by numbering each
element in the population and then selecting every kth number
from the population to be included in the sample
T distribution a family of bell-shaped curves based on Degrees
of freedom, similar to the standard normal Distribution with the
exception that the variance is Greater than 1; used when you are
testing small samples and when the population standard
deviation is unknown
                               124
T test a statistical test for the mean of a population, used when
the population is normally distributed and the Population
standard deviation is unknown
Test value the numerical value obtained from a statistical Test,
computed from (observed value _ expected value) _ Standard
error
Time series graph a graph that represents data that occur over
a specific time
Treatment group a group in an experimental study that has
received some type of treatment
Treatment groups the groups used in an ANOVA study
Tree diagram a device used to list all possibilities of a
Sequence of events in a systematic way
Tukey test a test used to make pairwise comparisons of Means
in an ANOVA study when samples are the same size
Two-tailed test a test that indicates that the null hypothesis
Should be rejected when the test value is in either of the
Two critical regions
Two-way ANOVA a study used to test the effects of two or
More independent variables and the possible interaction
Between them
                                125
Type I error the error that occurs if you reject the null
Hypothesis when it is true
Type II error the error that occurs if you do not reject the Null
hypothesis when it is false
Unbiased estimator an estimator whose value approximates
the expected value of a population Parameter, used for the
variance or standard deviation when the sample size is less than
30; an estimator whose Expected value or mean must be equal
to the mean of the Parameter being estimated
Unbiased sample a sample chosen at random from the
Population that is, for the most part, representative of the
Population
Ungrouped frequency distribution a distribution that uses
Individual data and has a small range of data
Uniform distribution a distribution whose values are evenly
distributed over its range
Upper class limit the upper value of a class in a frequency
Distribution that has the same decimal place value as the Data
Variable a characteristic or attribute that can assume Different
values
                               126
Variance the average of the squares of the distance that each
value is from the mean
Venn diagram a diagram used as a pictorial representative for
a probability concept or rule
Weighted mean the mean found by multiplying each value by
its corresponding weight and dividing by the sum of the weights
Wilcoxon rank sum test a nonparametric test used to test
Independent samples and compare distributions
Wilcoxon signed-rank test a nonparametric test used to Test
dependent samples and compare distributions
Within-group variance a variance estimate using all the
Sample data for an F test; it is not affected by differences in the
means
Z distribution see standard normal distribution
Z score see standard score
Z test a statistical test for means and proportions of a
Population, used when the population is normally distributed
and the population standard deviation is known
                                127
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