What is Human-Computer Interaction (HCI)?
Human-computer interaction (HCI) is a multidisciplinary field of study focusing on the
design of computer technology and, in particular, the interaction between humans (the users)
and computers.
Human Computer Interface (HCI) was previously known as the man-machine
studies or man-machine interaction. It deals with the design, execution and
assessment of computer systems and related phenomenon that are for human use.
HCI can be used in all disciplines wherever there is a possibility of computer
installation.
Some of the areas where HCI can be implemented with distinctive importance are
mentioned below −
● Computer Science − For application design and engi youneering.
● Psychology − For application of theories and analytical purpose.
● Sociology − For interaction between technology and organization.
● Industrial Design − For interactive products like mobile phones, microwave oven, etc.
Objective
The intention of this subject is to learn the ways of designing user-friendly interfaces
or interactions. Considering which, we will learn the following −
● Ways to design and assess interactive systems.
● Ways to reduce design time through cognitive system and task models.
● Procedures and heuristics for interactive system design.
Norman’s Seven Principles
Following are the seven principles of Norman −
● Use both knowledge in world & knowledge in the head.
● Simplify task structures.
● Make things visible.
● Get the mapping right (User mental model = Conceptual model = Designed model).
● Convert constrains into advantages (Physical constraints, Cultural constraints,
Technological constraints).
● Design for Error.
● When all else fails − Standardize.
Heuristic Evaluation
Heuristics evaluation is a methodical procedure to check user interface for usability
problems. Once a usability problem is detected in design, they are attended as an
integral part of constant design processes. Heuristic evaluation method includes
some usability principles such as Nielsen’s ten Usability principles.
Nielsen's Ten Heuristic Principles
● Visibility of system status.
● Match between system and real world.
● User control and freedom.
● Consistency and standards.
● Error prevention.
● Recognition rather than Recall.
● Flexibility and efficiency of use.
● Aesthetic and minimalist design.
● Help, diagnosis and recovery from errors.
● Documentation and Help
Hci goals
Safety
Utility
Effectiveness
Efficiency
Usability
Appeal
Hci benefits
1. Gaining market share
People intend to buy/use products with higher usability
e.g., Google’s search engine has the largest market share because it is easy to use with
higher efficiency
2. Improving productivity
Employees in a company perform their jobs in a faster manner
e.g., Intranet can increase employees’ efficiency
3. Lowering support costs
If the product is not usable, calls to customer support can be enormous
e.g., If a washing machine is difficult to use even after reading the instruction manual, many
users will call the customer service and the cost per call can be over $100
4. Reducing development cost
Avoid implementing features users don’t want and creating features that are annoying or
inefficient
e.g., If there are too many unnecessary confirmation dialog boxes in using a word processor,
it is likely this product needs to be redeveloped
Definations
Useful - means that the system supports user objectives.
Usable - means that it supports these objectives in easy-to-use ways.
Accessible - means that it can be used by the full range of intended users.
Key features of User Centered Design(UCSD)
1. A central focus on the people who will use the systems, on their preferences and
requirements
2. Building simple models of the users, the tasks and the technological systems
3. An iterative process
4. Prototyping and the evaluation of alternatives by users.
Core concepts of UCSD/Natural Computing
These are common to both natural computing and user-centred system design
User model
Universal access
Design for all
Inclusive design
Task models
Technological platform
Strengths and weaknesses of interactive systems
-Modern interactive systems can be powerful
-Interactive systems may provide useful functions
-Interactive systems differ in the extent that they are usable
-Accessibility varies between good and poorly designed system
