1. Principle of Human Computer Interaction

2. Introduction to HCI

3. Outline Introduction What is HCI? The goals of HCI What is Usability?
The HCI Challenge
HCI is Not about
HCI is about
The goals of HCI
What is Usability?
Why is usability important?
Why HCI is Important in the Context of WWW?
It is not Simple to Make Good User Interfaces
Examples of good and bad design

4. Introduction
Interacting with technology has become an essential part of everyday life for the majority of people.
The average user of a computer system is now less likely to understand the technology. Since, there are different types of technology they have to use.
People are busy and may spend little or no time actually learning a new system.

5. Introduction..(cont.)
Therefore, computer systems should be easy to use, easy to learn, and with no errors.
To design and develop of such a system is a major concern of HCI

6. What is HCI?
Human-computer interaction (HCI): “is a discipline concerned with the design, evaluation and implementation of interactive systems for human use and with study of major phenomena surrounding them.”
(ACM SIGCHI, 1992, p. 6)

7. What is HCI?
HCI (human-computer interaction) is the study of interaction between people (users) and computers.
Interaction between users and computers occurs at the user interface
The golden principle in HCI is that “people should come first”.

8. What ..(cont.) HCI consists of three parts:
Human: could be an individual user or a group of users.
Computer: could be any technology ranging from the general desktop computer to a large scale computer system.
Interaction: any direct or indirect communication between a human and computer.

9. What ..(cont.) HCI concentrates on the study of human factors
The study of human factors started during the Second World War by US army.
Usability was born because of badly designed arms that caused “friendly fire” during war.

10. The HCI Challenge

11. HCI is Not about Making the interface look pretty
Only about desktop computers (and that goes for computing as well!)
Something that would be nice to do but usually there’s no time for it

12. HCI is about Understanding the users Understanding users tasks
Understanding the surrounding environment
GUI requirements gathering and analysis
Design prototype
Evaluate the system

13. The goals of HCI
The goal of HCI “is to develop or improve the safety, utility, effectiveness, efficiency and usability of system that include computers.”
(Interacting with computers, 1989, p3)

14. The goals of HCI
The goals of HCI are to produce usable and safe systems, as well as functional systems. In order to fulfill that, developers must attempt to:
Understand how people use technology
Building suitable systems
Achieve efficient, effective, and safe interaction
Put people first
People needs, capabilities and preferences should come first. People should not have to change the way that they use a system. Instead, the system should be designed to match their requirements

15. What is Usability? A usable system is: easy to use easy to learn
easy to remember how to use
effective to use
efficient to use
safe to use
enjoyable to use

16. Why is usability important?
A Good user-interface can:
1. Earn a company billions.
2. Increase users loyalty.
3. Increase users trust.
4. Makes users happy : )

17. Why ..(cont.)
A Bad user-interface can: 1. be annoying, embarrassing, frustrating, and even deadly. 2. Increase mistakes in data entry and system operation. 3. Makes functions become completely inaccessible. 4. System failure because of user rejection.

18. Why HCI is Important in the Context of WWW?
• Competition is very close (just another link…) • Comparison is easily possible (example – Online-Shop) • Users who can’t find the product in the shop can not buy it • Users who are not able to fill in correctly the order form are not going to buy

19. It is not Simple to Make Good User Interfaces
Basic misconceptions: • If I (the developer) can use it, everyone can use it • If our non-technical staff can use it, everyone can • Good user interfaces are applied common sense • A system is usable if all style guidelines are met

20. Examples of good and bad design

21. Examples ..(cont.)

22. Examples ..(cont.)

23. Examples ..(cont.)

24. Usability requirements
Synonyms for “user-friendly” in Microsoft Word 2002 are: easy to use; accessible; comprehensible; intelligible; idiot proof; available; and ready
These measures are still subjective, so a systematic process is necessary to develop usable systems for specific users in a specific context

25. Goals for requirements analysis
Ascertain the user’s needs
Determine what tasks and subtasks must be carried out
Include tasks which are only performed occasionally. Common tasks are easy to identify.
Functionality must match need or else users will reject or underutilize the product

26. Goals for requirements analysis
Ensure reliability
Actions must function as specified
Database data displayed must reflect the actual database
The system should be available as often as possible
The system must not introduce errors
Ensure the user's privacy and data security by protecting against unwarranted access, destruction of data, and malicious tampering

27. Goals for requirements analysis
Ensure reliability
Actions must function as specified
Database data displayed must reflect the actual database
The system should be available as often as possible
The system must not introduce errors
Ensure the user's privacy and data security by protecting against unwarranted access, destruction of data, and malicious tampering

28. Goals for requirements analysis
Complete projects on time and within budget Late or over budget products can create serious pressure within a company and potentially mean dissatisfied customers and loss of business to competitors

29. Usability measures
Define the target user community and class of tasks associated with the interface
5 human factors central to community evaluation:
Time to learn How long does it take for typical members of the community to learn relevant task?
Speed of performance How long does it take to perform relevant benchmarks?
Rate of errors by users How many and what kinds of errors are made during benchmark tasks?
Subjective satisfaction Allow for user feedback via interviews, free-form comments and satisfaction scales

30. Universal Usability Physical abilities and physical workplaces
Basic data about human dimensions comes from research in anthropometry
There is no average user, either compromises must be made or multiple versions of a system must be created
Physical measurement of human dimensions are not enough

31. Universal Usability (cont.)
Personality differences
There is no set taxonomy for identifying user personality types
Designers must be aware that populations are subdivided and that these subdivisions have various responses to different stimuli

32. Universal Usability (cont.)
Gender differences
No clear patterns have emerged
Games
Tend to be aimed at young males
Highest demographic of online players: older women
Productivity tools
Largely male designers

33. Universal Usability (cont.)
Users with disabilities
Designers must plan early to accommodate users with disabilities
Early planning is more cost efficient than adding on later
Businesses must comply with the "Americans With Disabilities" Act for some applications
Designing for/with children
Broad term: toddlers to teenagers
Parental control and safety vs desire of challenge and learning
Elderly Users
Including the elderly is fairly ease, designers should allow for variability within their applications via settings for sound, color, brightness, font sizes, etc.

34. Universal Usability (cont.)
Some practical user types
The Beginner
Just starting out, possibly not very technical
Will need lots of hand-holding, at least to start
Ever try teaching your grandmother AOL?
The Casual User
Uses the system infrequently
Uses short-cuts, occasionally needs help
The “Technically Challenged” User
Doesn’t know, doesn’t want to know!
Will need lots of hand-holding (i.e., help system)

35. Universal Usability (cont.)
Some more practical user types
The Power User
Frequent user, loves the features, pushes all buttons
Wants efficiency and customization
The Technical Guru
“If I had written this…”
Probably lots of pre-conceptions

36. Usability Topic: Color Blindness
About 8% of men have color blindness of some type, and about 0.5% of women
Misnomer: most people see color difference of some kind
Color deficiency
Monochromacy, very rare condition
Genetic condition, alteration of the cones in the eye

37. Types of Color Blindness
Protanopia – L-cone (“red weak”)
Deutanopia – M-cone (“green weak”)
Tritanopia – S-cone (yellow/blue)

38. What Color Blindness Looks Like
Normal Deutanopia Tritanopia

39. What Color Blindness Looks Like
Normal Deutanopia Protanpoia

40. What To Do Is Color Blindness curable?
Medically speaking, no
Can we (UI designers) work around it?
Certainly

41. Designing for Color Blindness
Avoid red-on-green at all costs!
Consider using magenta instead of red
Avoid using magenta with blue
Use redundant coding of information
Use color and shape/location
Avoid thin lines / small symbols
For color-coded text, use bold fonts

42. The End