Psychometry:
An Introduction
Psychometrics: An intro
Psychometry
Itis measurement of psychological
variables/different aspects of behaviour.
Measurement - refers to the process of
assigning numerals to attributes of
objects according to certain rules.
Psychometrics: An intro
Properties of measurement
The rules are vague and less explicit for
measuring psychological, sociological and
educational attributes
In the process of measurement, numerals
are used to represent quantities of the
attributes
Psychometrics: An intro
A brief history
Modern psychometrics dates to
Sir Francis Galton (1822-1911),
Charles Darwin’s cousin
• Interested in individual differences
and their distribution
• 1884-1890: Tested 17000 individuals
on height, weight, behavior: hand
strength, visual acuity, etc
• Demonstrated that objective tests could
provide meaningful scores
• Invented correlation
Psychometrics: An intro
James Cattell first used the term ‘mental test’ in
1890
• His tests were in the ‘brass
instruments’ tradition of Galton
• mostly motor and acuity tests
Alfred Binet (1905) introduced the
first modern intelligence test, which
directly tested higher psychological
processes (real abilities & practical
judgments)
Psychometrics: An intro
What is a psychological test?
A test is
a series of questions on the basis of which
some information is sought.
Definition:
A psychological test is a standardized procedure to
measure quantitatively or qualitatively one or more
than one aspect of a trait by means of a sample of
verbal or nonverbal behaviour.
A psychological test is essentially an objective and
standardized measure of sample of behaviour.
( Anastasi & Urbina; 1997)
Psychometrics: An intro
Features of a psychological test
1. Test is an organized succession of
stimuli/ items
2. Both quantitative and qualitative
measurements are possible
3. It is based upon a limited sample of
behaviour
4. Tests provide scores which is interpreted
with reference to a standardized sample
Psychometrics: An intro
Two fold purpose of a psychological
test:-
1. It attempts to compare the same
individual on two or more than two
aspects of a trait
2. Two or more persons may be compared
on the same trait
Psychometrics: An intro
Characteristics of a psychological
test
1. Objectivity
2. Reliability
3. Validity
4. Norms
5. Practicability
Psychometrics: An intro
1. Objectivity
A test must be free from subjective element
Two aspects:-
1.Objectivity of items: Items should be phrased
in such a manner that they are interpreted
inexactly the same way by all those who take
the test
2. Objectivity of scoring: standard scoring
method so that complete uniformity can be
maintained when the test is scored by diff
experts at diff times
Psychometrics: An intro
2. Reliability
It shows the extent to which the results obtained
are consistent when the test is administered
once or more than once on the same sample
with a reasonable time gap
Two types of Consistency:-
Internal Consistency: consistency in results
obtained in a single administration of the test
Temporal Consistency: consistency in results
obtained upon testing and retesting after a time
gap
Psychometrics: An intro
3. Validity
It shows the extent to which the test
measures what it intends to measure
It is the correlation of the test with some
outside independent criterion
It depends on the PURPOSE
E.g. a ruler may be a valid measuring
device for length, but isn’t very valid for
measuring volume
Measuring what ‘it’ is supposed to
Psychometrics: An intro
Validity and Reliability
Think in terms of ‘the purpose of tests’ and the
‘consistency’ with which the purpose is fulfilled/met
Neither Valid Reliable but not
nor Reliable Valid
Fairly Valid but Valid &
not very Reliable
Reliable
4. Norms
Norms refer to the average
performance of a representative
sample on a given test
It helps in the interpretation of the
scores of the test
Psychometrics: An intro
5. Practicability
A test must be practicable from the
point of view of time taken in its
completion, length, scoring etc
A test should not be lengthy and scoring
must not be difficult
Psychometrics: An intro
CLASSIFICATION OF
TEST
Psychometrics: An intro
Classification of test
1. On the basis of the criterion of administrative
conditions
2. On the basis of the criterion of Scoring
3. On the basis of the criterion of time limit in
producing the response
4. On the basis of the criterion of the nature or
contents of items
5. On the basis of the criterion of purpose or
objective
6. On the basis of the criterion of
standardization
Psychometrics: An intro
I) On the basis of the criterion of
administrative conditions
Two types:-
1. Individual Tests- test administered to one
person at a time. E.g. Kohs Block Design Test
2. Group Tests- Tests used with more than one
person at a time. E.g. Bell adjustment
inventory
Psychometrics: An intro
II) On the basis of the criterion of Scoring
Two types:-
1. Objective Tests
2. Subjective Tests
1. Objective Tests- test scored in such a way that no
scope for subjective judgment exists and thus it is
unambiguous . E.g. Multiple choice, True or false,
matching Test
In such items, the problem(Stem) as well as its
answer is given along with the distractors.
also known as New type tests or Limited answer
tests
Psychometrics: An intro
2. Subjective Tests- Tests scored in a way in
which there exists some scope for
subjective judgment.
Also called as Essay tests or Free answer
tests
E.g. What are the major goals of
Counselling?
Psychometrics: An intro
III)On the basis of the criterion of
time limit in producing the response
Two types:-
1. Power test
2. Speed test
1. Power Test- A Test which has generous time
limit so that most examinees are able to attempt
every item
Items are arranged in increasing order of
difficulties
E.g. Intelligence tests, aptitude tests
Psychometrics: An intro
2. Speed Test- A Test which has severe time
limits but the items are comparatively easy
so that very few examinees make errors.
Items are of the same difficulty level
E.g. Clerical aptitude tests
It reveals with what speed the examinees
can respond with in a given time limit
Psychometrics: An intro
IV)On the basis of the criterion of
nature or contents of items
Four types:-
1.Verbal test
2. Non verbal test
3. Performance test
4. Non language test
1. Verbal Test- A test whose items emphasize
reading, writing and oral expression as the
primary mode of communication
paper pencil tests
eg:- Jalota group intelligence test
Psychometrics: An intro
2. Non Verbal Test- A Test whose items don’t use
language but it is used in instruction.
Test items in the form of figures and symbols
Eg. RPM
3. Performance Test- it requires the examinees to
perform a task rather than answer some
questions.
Instruction is given orally or through gesture
Eg. Assembling a puzzle, Kohs block design and
pass along test
Psychometrics: An intro
4. Non language Test- A Test whose items don’t
depend upon any form of written, spoken or
reading communication.
Test items in the form of figures and symbols
Instruction is given through gesture
Eg. Tests for dumb and non communicative
children
Psychometrics: An intro
V) On the basis of the criterion of purpose or objective
Intelligence tests: Assess ‘intelligence’
Aptitude tests: Assess capability
Achievement tests: Assess degree of accomplishment
Creativity tests: Assess capacity for novelty
Personality tests: Assess traits
Interest inventories: Assess preferences for activities
Behavioral tests: Measure behaviors and their
antecedents/consequences
Neuropsychological tests: Measure cognitive, sensory,
perceptual, or motor functions
Psychometrics: An intro
VI)On the basis of the criterion of standardization
Two types:-
1. Standardized test:- Test constructed by test
specialists which have been administered and
scored under standard and uniform testing
conditions.
It should have reliability, validity and norms
2. Teacher made test- tests constructed by teachers
for use largely with in their class room.
Psychometrics: An intro
Uses of Psychological Tests
1. To acquire knowledge about certain attributes of
an indvl/ group
2. To compare indvls/ groups
3. In the selection and classification of individuals
4. In diagnosis and planning for treatment
5. Tests enhance self understanding and personal
dvpt
Psychometrics: An intro
Uses of Psychological Tests
6. In basic research to gather data
7. In evaluation of programmes
8. Prediction
Psychometrics: An intro
Limitations
a. Invasion of privacy
b. It permanently categorize persons
c. It measure only limited aspects of bhvr
d. Create anxiety in the examinees
e. Penalize bright and creative examinees
Psychometrics: An intro
Thank you
Psychometrics: An intro
