Usability, Accessibility, and Design Evaluation

Design EvaluationDamian Gordon

The Design of Everyday Things by Donald Norman

“The human mind is exquisitely tailored to make sense of the world. Give it the slightest clue and off it goes, providing explanation, rationalization, understanding. Consider the objects – nooks, radios, kitchen, appliances, office machines, and light switches – that make up our everyday lives. Well- designed objects are easy to interpret and understand. They contain visible clues to their operation.

Poorly designed objects can be difficult and frustrating to use. They provide no clues – or sometimes false clues. They trap the user and thwart the normal processing interpretation and understanding…The result is a world filled with frustration.”

A key issue is usability. Usability is the ease of use and learnability

of a human-made object. The object of use can be a software

application, website, book, tool, machine, process, or anything a human interacts with.

Usability

A usability study may be conducted as a primary job function by a usability analyst or as a secondary job function by designers, technical writers, marketing personnel, and others.

It is widely used in consumer electronics, communication, and knowledge transfer objects (such as a cookbook, a document or online help) and mechanical objects such as a door handle or a hammer.

Usability

Usability includes methods of measuring usability and the study of the principles behind an object's perceived efficiency or elegance.

In human-computer interaction and computer science, usability studies the elegance and clarity with which the interaction with a computer program or a web site (web usability) is designed.

Usability

Born 5 Oct 1957 Born in Copenhagen,

Denmark a leading web usability

consultant founded the "discount

usability engineering" movement for fast and cheap improvements of user interfaces and has invented several usability methods.

Jakob Nielsen

F-Shaped Pattern For Reading Web Content

This dominant reading pattern looks somewhat like an F and has the following three components:


Users first read in a horizontal movement, usually across the upper part of the content area. This initial element forms the F's top bar.


Next, users move down the page a bit and then read across in a second horizontal movement that typically covers a shorter area than the previous movement. This additional element forms the F's lower bar.


Finally, users scan the content's left side in a vertical movement. Sometimes this is a fairly slow and systematic scan that appears as a solid stripe on an eyetracking heatmap. Other times users move faster, creating a spottier heatmap. This last element forms the F's stem.


Users won't read your text thoroughly in a word-by-word manner. Exhaustive reading is rare, especially when prospective customers are conducting their initial research to compile a shortlist of vendors. Yes, some people will read more, but most won't.

The first two paragraphs must state the most important information. There's some hope that users will actually read this material, though they'll probably read more of the first paragraph than the second.

Start subheads, paragraphs, and bullet points with information-carrying words that users will notice when scanning down the left side of your content in the final stem of their F-behavior. They'll read the third word on a line much less often than the first two words.


Nielsen’s Heuristics

Nielsen’s Heuristics1. Visibility of system status2. Match between system and the real world3. User control and freedom4. Consistency and standards5. Error prevention6. Recognition rather than recall7. Flexibility and efficiency of use8. Aesthetic and minimalist design9. Help users recognize, diagnose, and recover from errors10. Help and documentation

15


1. Visibility of system status

The system should always keep users informed about what is going on, through appropriate feedback within reasonable time.

16


2. Match between system and the real world

The system should speak the users' language, with words, phrases and concepts familiar to the user, rather than system-oriented terms. Follow real-world conventions, making information appear in a natural and logical order.

17


3. User control and freedom

Users often choose system functions by mistake and will need a clearly marked "emergency exit" to leave the unwanted state without having to go through an extended dialogue. Support undo and redo.

18


4. Consistency and standards

Users should not have to wonder whether different words, situations, or actions mean the same thing. Follow platform conventions.

19


5. Error prevention

Even better than good error messages is a careful design which prevents a problem from occurring in the first place. Either eliminate error-prone conditions or check for them and present users with a confirmation option before they commit to the action.

20


6. Recognition rather than recall

Minimize the user's memory load by making objects, actions, and options visible. The user should not have to remember information from one part of the dialogue to another. Instructions for use of the system should be visible or easily retrievable whenever appropriate.

21


7. Flexibility and efficiency of use

Accelerators -- unseen by the novice user -- may often speed up the interaction for the expert user such that the system can cater to both inexperienced and experienced users. Allow users to tailor frequent actions.

22


8. Aesthetic and minimalist design

Dialogues should not contain information which is irrelevant or rarely needed. Every extra unit of information in a dialogue competes with the relevant units of information and diminishes their relative visibility.

23


9. Help users recognize, diagnose, and recover from errors

Error messages should be expressed in plain language (no codes), precisely indicate the problem, and constructively suggest a solution.

24

10. Help and documentation

Even though it is better if the system can be used without documentation, it may be necessary to provide help and documentation. Any such information should be easy to search, focused on the user's task, list concrete steps to be carried out, and not be too large.

25


Seven Principles of Universal Design

Seven Principles of Universal Design (which you are familiar with)1. Equitable Use2. Flexibility in Use3. Simple and Intuitive4. Perceptible Information5. Tolerance for Error6. Low Physical Effort7. Size and Space for Approach and Use

27

Equitable Use• Provide the same means of use for all

users: identical whenever possible; equivalent when not

• Avoid segregating or stigmatising any users• Provisions for privacy, security and safety

should be equally available to all users• Make the design appealing to all users

28

Equitable Use

29

Flexibility in Use• Provide choice in method of use• Accommodate right-handed or left-handed

access and use• Facilitate the user’s accuracy and precision• Provide adaptability to the user’s pace

30

Flexibility in Use

31

Simple and Intuitive• Eliminate unnecessary complexity• Be consistent with user expectations and

intuition• Accommodate a wide range of literacy and

language skills• Arrange information consistent with its

importance• Provide effective prompting and feedback

during and after task completion

32

Simple and Intuitive

33

Perceptible Information• Use different modes (pictorial, verbal, tactile) for redundant

presentation of essential information• Provide adequate contrast between essential information

and its surroundings• Maximise legibility of essential information and its

surroundings• Differentiate elements in ways that can be described (i.e.

make it easy to give instructions or directions)• Provide compatibility with a variety of techniques or

devices used by people with sensory limitations

34

Perceptible Information

35

Tolerance for Error• Arrange elements to minimise hazards and

errors: most used elements, most accessible; hazardous elements eliminated, isolated or shielded

• Provide warnings of hazards and errors• Provide fail safe features• Discourage unconscious action in tasks that

require vigilance

36

Tolerance for Error

37

Low Physical Effort• Allow user to maintain a neutral body

position• Use reasonable operating forces• Minimise repetitive actions• Minimise sustained physical effort

38

Low Physical Effort

39

Size and Space for Approach and Use

• Provide a clear line of sight to important elements for any seated or standing user

• Make reach to all components comfortable for any seated or standing user

• Accommodate variations in hand and grip size

• Provide adequate space for the use of assistive devices or personal assistance

40

Size and Space for Approach and Use

41

8 Golden Rules of Interface Design1. Strive for consistency2. Cater to universal usability3. Offer informative feedback4. Design dialogs to yield closure5. Prevent errors6. Permit easy reversal of actions7. Support internal locus of control8. Reduce short term memory

42

13 Principles of Display DesignPerceptual Principles1. Make displays legible (or audible)2. Avoid absolute judgment limits3. Top-down processing4. Redundancy gain5. Similarity causes confusion: Use discriminable elementsMental Model Principles6. Principle of pictorial realism7. Principle of the moving partPrinciples Based on Attention8. Minimizing information access cost9. Proximity compatibility principle10. Principle of multiple resourcesMemory Principles11. Replace memory with visual information: knowledge in the world12. Principle of predictive aiding13. Principle of consistency

1 Anticipation2 Autonomy3 Colour Blindness4 Consistency5 Defaults6 Efficiency of the User7 Explorable Interfaces8 Fitts' Law

Bruce Tognazzini's First Principles of Interaction Design

9 Human-Interface Objects

10 Latency Reduction11 Learnability12 Metaphors13 Protect the User's

Work14 Readability15 Track State16 Visible Interfaces

Six Thinking Hats

FOCUS

Information & DataNeutral and objectiveChecked and believed factsMissing information & Where to source it

Managing the ThinkingSetting the focusMaking summariesOverviews & conclusionsAction Plans

Why it may not workCautions * DangersProblems * FaultsLogical reasons must be given

Why it may workValues * Benefits(both known and potential)Logical reasons must be given

Creative ThinkingPossibilities * AlternativesNew Ideas * New ThinkingOvercome black hat issuesReinforce yellow hat issues

Feelings and IntuitionEmotions and hunchesNo reasons or justifications“At this point”Keep it short

Dieter Rams’ Principles of Design

1. Creative Design2. Aesthetic Design3. Sustainable Design4. Consistent Design5. Understandable Design6. Unobtrusive Design7. Useful Design8. Minimalist Design9. Thorough design10. Honest Design

Usability, Accessibility, and Design Evaluation

Education

Transcript of Usability, Accessibility, and Design Evaluation