2. เปาหมายของการติดตอประสานของมนุษยและ
HCI Importance คอมพิวเตอร
A survey by Myers and Rosson (1992) สรางสรรคสวนประสานติดตอของผูใชกับคอมพิวเตอร (Interface)
"The average time [developers] spent on ซึ่งรูปลักษณของอินเตอรเฟสสงผลอยางมากตอการที่ผูใชมองและเขาใจในหนาที่
าใจในหน
การทํางานของสิ่งนั่นๆ
the user interface portion is 45% during
เพื่อใหเกิดผลสัมฤทธิ์ทางการปฏิบัติ (Performance) เชน ปลอดภัย
the design phase, 50% during the รวดเร็ว ถูกตอง ซึ่งเกิดการการกระทําตามลักษณะทางกายภาพของผูใช
implementation phase, and 37% during (Physical Aspects) และ ลักษณะทางความคิด (Cognitive
the maintenance phase." Aspects )
และเกิดความพึงพอใจสูงสุด (Satisfaction) เชน สนุกสนาน สวยงาม นา
ใช
โดยเนนที่การสรางสรรคที่สอดคลองกับความตองการของผูใช สอดคลองกับงาน
ของผูใช และสอดคลองกับสิ่งแวดลอมของผูใช หรือที่เรียกวา การออกแบบที่เนน
7
ผูใชเปนศูนยกลาง (User-Centered Design)
(User- 8
HCI Scope HCI Factors
Organizational Factors Environmental Factors
Training, job design, policies, roles, org. Noise, heating, lighting
The capability of the human brain and the senses used
in HCI Health & Safety Factors User Comfort Factors
Stress, headaches, blood Cognitive processes, capabilities, motivation, Seating, equipment layout
The human ability to learn to use computing systems pressure satisfaction, personality, experience level
The context of the joint performance of tasks by humans User Interface
and computing systems, called ethnography Input devices, output displays, dialogue structures, use of color, icons, graphics, natural language, 3-D
Structures of communication between human and Task Factors
machine Easy, complex, novel, task allocation, repetitive, monitoring, skills, components
Human task analysis and how the computer contributes Constraints
to successful task completion Costs, timescales, budgets, staff, equipment, building structure
Design of user interfaces
System Functionality
Implementation of user interfaces Hardware, software, application
Evaluation of user interfaces and design tradeoffs
Productivity Factors
9 Increase output, increase quality, decrease costs, decrease errors, decrease production time 10
Software development life cycle Systems Development Life
(SDLC) Cycle
Analysis
Study of current procedures and information
systems
• Determine requirements
Study current system
Structure requirements and eliminate redundancies
• Generate alternative designs
• Compare alternatives
• Recommend best alternative
1.12
11 12
2
3. Systems Development Life Systems Development Life
Cycle Cycle
Design Maintenance
Logical Design • System changed to reflect changing conditions
• Concentrates on business aspects of the system
• System obsolescence
Physical Design
• Technical specifications
Implementation
Implementation
• Hardware and software installation
• Programming
• User Training
• Documentation
1.13 1.14
13 14
The New User-Centered Software
User-
Star Life Cycle
Development Life Cycle
Involving users at all stages of the development;
observing working environment, using models of
users, and including some users on the design
team.
Applying knowledge from all HCI-related
HCI-
disciplines integrated with the software
development; employing design guidelines and
principles.
Using highly iterative testing with user feedback
after each iteration.
15 16
Usability Engineering (Cont.) Usability Engineering (Cont.)
Usability How can you design a product so that it is sure to appeal to
customers?
“ The effectiveness, efficiency, and satisfaction How do you meet the challenge of creating software to handle hugehuge
with which specified users achieve specified increases in online activity and serve the user’s need for a tool that
user’
is easy to manage?
goals in particular environment.” (ISO 9241-11)
environment.” 9241- How do you go about designing a product that people find usable,
Learnability, Efficiency, Memorability, Errors, and
Learnability, Memorability, regardless of individual differences in learning style and depth of
experience with technology?
Satisfaction (Nielsen, 1994) As products become more complex, what steps should be taken to
ensure that they will remain effective and intuitive?
How can a company change its product development process and
underlying culture to be more user- or customer-centered?
user- customer-
17 18
3
4. Usability Engineering (Cont.) Usability Engineering (Cont.)
Usability Engineering Software industry studies suggest that an investment in
usability engineering can produce a return on investment in
Coined by DEC (Good, et al. 1986) the range of 3:1 to 100:1.
Concepts and techniques for planning, achieving, and Usability engineering benefits
verifying objectives for system usability Fewer last-minute design changes
last-
a discipline that incorporates user interface design Usable, appealing, and effective designs
and usability testing. Simpler, less costly documentation
*Measurable usability goals must be defined early in Credible marketing claims
software development, and then assessed repeatedly Compelling product demonstrations
during development to ensure that they are achieved Increased sales
(Bennett 1984; Gilb 1984). Reduced need for customer support
Longer market life
19 20
Usability Engineering (Cont.)
The Stages of the Usability Lifecycle Model (Nielsen, 1994)
1. Know the user
Individual user characteristics, the user’s current and desired
user’
task, functional analysis, and the evolution of the user and
job
2. Competitive analysis
3. Setting usability goals
Financial impact analysis
4. Parallel design
5. Participatory design
6. Coordinated design of the total interface
7. Apply guidelines and heuristic analysis
8. Prototyping
9. Empirical testing
10. Iterative design
Capture design rationale
11. Collect feedback from field use
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