Components of HCI

1
Components of HCI

• HCI is interdisciplinary practice

2
Ideal Software Design Team should have expertise
in

• software design engineering
• functional spec design
• visual interface design
• prototyping
• usability testing
• marketing
• writing

3
Who are those people?

• Programmer
• User interface designer
• Graphic designer
• Human factors specialist
• Documentation writer

4
HCI areas of Interest

• Computer Science
• Cognitive Psychology
• Social and Organization Psychology
• Ergonomics / Human Factors
• Engineering
• Design

5
HCI -- more areas of Interest

• Anthropology
• Sociology
• Philosophy
• Linguistics
• Artificial intelligence

6
Computer Science

• systematic study of algorithmic processes
• computer programming

7
Cognitive Psychology

• perception
• attention
• memory
• learning
• thinking
• problem solving

8
Objective of cognitive psychology
To characterize these processes in terms of their
capabilities and limitations. Donald Norman -
The Psychology of Everyday Things
9
HCI incorporates cognitive psychology principles
by

• the use of models to predict human performance
• developing guidelines
• use of empirical methods for testing computer
  systems.

10
Social Psychology

• is concerned with studying the nature and causes
  of human behavior in a social context.
• multi-user centered designs
• user centered computer designs

11
Objective of Ergonomics

• maximize an operators safety
• efficiency
• reliability of performance
• make a task easier
• increase feelings of comfort and satisfaction.

12
Terry Winograd

• Human-computer interaction is the kind of
  discipline which is neither the study of humans,
  nor the study of technology, but rather the
  bridging between those two.

13
Designing HCI

• 4 Conceptual Models

14
HCI model (Easton, 1991)

• People
• Work
• Environment
• Technology

15
A Model of HCI (adapted from Eason)
Levels of analysis in HCI
Organizational Goal
Level 3
Social System
Level 2
Work
Technical system
Broader Environment
Intermediate environment
Level 1
Technology
People
16
Carroll - Task-artifact

• In order to design better systems we need a
  better understanding of the tasks that people do
  or want to do so that we can use this knowledge
  to influence design

Requirements
Tasks
Artifacts
Possibilities
17
Waterfall Model (Sommerville, 1992)
Requirements analysis and definition
System and software design
Implementation and unit testing
Integration and system testing
18
Star Life Cycle (Hix Hartson, 1993)
Task analysis/ functional analysis
Implementation
Requirements specification
Evaluation
Prototyping
Conceptual design/ formal design
19
Supermarket / barcode Reader
20
Supermarket / barcode Reader
How will computerized system affect them? How
easy will it be for them to use it? What changes
will be made in roles and work practices?
21
Cognitive Frameworks for HCI

• cognitive perspective
• cognitive framework

22
Cognition

• refers to the processes by which we become
  acquainted with things or, in other words, how we
  gain knowledge.
• These include understanding, remembering,
  reasoning, attending, being aware, acquiring
  skills and creating new ideas.

23
Main objective

• to understand and represent how humans interact
  with computers in terms of how knowledge is
  transmitted between the two.

24
Human Information Processing Model. (Barber, 1988)
Input
Output
Response Selection
Response Execution
Encoding
Comparison
25
Extended stages of the Information Processing
Model. (Barber, 1988)
Attention
Input
Output
Response Selection
Response Execution
Encoding
Comparison
Memory
26
Multi-store model of memory

• Sensory store
• look out window
• 4 volunteers (reading)
• short-term memory store (working memory)
• get out a piece of paper number A - T
• 7 - 2 - Chunking
• long-term memory store
• What was Alan Coopers User Goals

27
Which paragraph is easier to read?

• DESIGN COMPUTER SYSTEMS TO MATCH USERS NEEDS ,
  IT IS NECESSARY TO CONSIDER THE CONTEXT IN WHICH
  THEY ARE TO BE USED.
• Design computer systems to match users needs ,
  it is necessary to consider the context in which
  they are to be used.