User Interface Evaluation

1
User Interface Evaluation

• Usability Inspection Methods
• http//jthom.best.vwh.net/usability/
• http//www.cs.umd.edu/zzj/UsabilityHome.html

2
Usability Inspection Methods

• Usability experts inspect your interfaces
  during formative evaluation.
• Widely used in practice.
• Often abused by developers that consider
  themselves to be usability experts.

3
Usability Inspection Methods

• Heuristic Evaluation
• Cognitive Walkthroughs
• Pluralistic Walkthroughs
• Feature, Consistency Standards Inspection

4
Heuristic Evaluation

• Applicable Stages
• Design, Code, Test Deployment
• Personnel
• Usability Experts, approximately 4.
• Developers, 0.
• Users, 0.

5
Heuristic Evaluation

• Usability Issues Covered
• Effectiveness Yes
• Efficiency Yes
• Satisfaction No
• Quantitative Data is not collected.
• Can be conducted remotely.
• Can be used on any system.

6
Heuristic Evaluation

• What is it?
• Several evaluators independently evaluate the
  interface come up with potential usability
  problems.
• It is important that there be several of these
  evaluators and that the evaluations be done
  independently.
• Nielsen's experience indicates that around 5
  evaluators usually results in about 75 of the
  overall usability problems being discovered.

7
Heuristic Evaluation

• How can I do it?
• Obtain the service of 4, 5 or 6 usability
  experts.
• Each expert will perform an independent
  evaluation.
• Give experts a heuristics inspection guide.
• Collect the individual evaluations.
• Bring the experts together and do a group
  heuristic evaluation. (Optional)
• http//www.cs.umd.edu/zzj/Heuristi.htm

8
Cognitive Walkthroughs

• Applicable Stages
• Design, Code, Test Deployment
• Personnel
• Usability Experts, approximately 1 - 4.
• Developers, 0 - 2.
• Users, 0.

9
Cognitive Walkthroughs

• Usability Issues Covered
• Effectiveness Yes
• Efficiency No
• Satisfaction No
• Quantitative Data is not collected.
• Can NOT be conducted remotely.
• Can be used on any system, but works best on
  systems that you can walk up and use systems that
  dont require explicit learning.

10
Cognitive Walkthroughs

• What is it?
• Cognitive walkthroughs involve one or a group of
  evaluators inspecting a user interface by going
  through a set of tasks and evaluate its
  understandability and ease of learning.
• The input to the walkthrough also include the
  user profile, especially the users' knowledge of
  the task domain and of the interface, and the
  task cases.
• Based upon exploratory learning methods.
• Exploration of the user interface.

11
Cognitive Walkthroughs

• What is it?
• The evaluators may include
• Human factors engineers
• Software developers
• People from marketing
• Documentation, etc.
• Best used in the design stage of development.

12
Cognitive Walkthroughs

• How can I do it?
• Select the participants, who will be involved?
• Select the tasks, what task will be examined?
• Select the interfaces, which interface(s) will be
  evaluated?

13
Cognitive Walkthroughs

• How can I do it?
• During the walkthrough
• Illustrate the task and then ask a user to
  perform a task.
• Accept input from all participants do not
  interrupt demo.
• After the walkthrough
• Make interface changes.
• Plan the next evaluation.
• http//www.cs.umd.edu/zzj/CognWalk.htm

14
Pluralistic Walkthroughs

• Applicable Stages
• Design
• Personnel
• Usability Experts, approximately 1.
• Developers, 1.
• Users, 2.

15
Pluralistic Walkthroughs

• Usability Issues Covered
• Effectiveness Yes
• Efficiency No
• Satisfaction Yes
• Quantitative Data is not collected.
• Can NOT be conducted remotely.
• Can be used on any system, but works best on
  systems that you can walk up and use systems that
  dont require explicit learning.

16
Pluralistic Walkthroughs

• What is it?
• During the design stage, a group of people
• Users
• Developers
• Usability Experts
• Meet to perform a walkthrough.

17
Pluralistic Walkthroughs

• How can I do it?
• The group meets and 1 person acts as coordinator.
• A task is presented to the group.
• Paper prototypes, screen shots, etc. are
  presented.
• Each participants write down comments on each
  interface.
• After the demo, a discussion will follow.
• http//www.cs.umd.edu/zzj/PlurWalk.htm

18
Feature, Consistency Standards Inspection

• Applicable Stages
• Code, Testing and Deployment
• Personnel
• Usability Experts, approximately 1.
• Developers, 0.
• Users, 0.

19
Feature, Consistency Standards Inspection

• Usability Issues Covered
• Effectiveness Yes
• Efficiency No
• Satisfaction No
• Quantitative Data is not collected.
• Can be conducted remotely.
• Works best on in house systems that have
  standards.

20
Feature, Consistency Standards Inspection

• What is it?
• Feature, Consistency Standards are inspected by
  an expert.

21
Feature, Consistency Standards Inspection

• How can I do it?
• Feature Inspection
• The expert is given use cases/scenarios and asked
  to inspect the system.
• Consistency Inspection
• The expert is asked to inspect consistency within
  your application.
• Standards Inspection
• The expert is asked to inspect standards.
• Standards can be in house, government, etc.

22
Heuristic Evaluation

• A Closer Look At How To
• Evaluate Interfaces

23
A Closer Look At Heuristic Evaluation

• Evaluation is easier than design.
• The principles that drive design, drive
  evaluation as well.

24
5 Human Factors Principles

• Language
• Layout
• Color
• Tone Etiquette
• Special Considerations such as standards,
  disabilities, etc.

25
Evaluating Language

• What is the language?
• English, Chinese, Hindi, etc.
• Do the text messages convey a message?
• If so, what is the message?
• Is the text long, short, organized, etc.

26
Evaluating Layout

• Symmetry
• Is the interface symmetrical?
• Left-Right, Top-Bottom, Center
• Attention Focus
• Where does your attention focus go?

27
Evaluating Color

• Contrast
• Are the color contrasts good?
• What meanings do the colors convey?
• Pink its a girl.
• Blue its a boy.

28
Evaluating Tone Etiquette

• Is the language offensive?
• Are the messages polite?
• Will the content offend anyone?

29
Evaluating Special Considerations

• Features, Consistency Standards.
• Does it work the way it is suppose to work?
• Is it consistent?
• Does it follow the standards?
• Disabilities

30
Affordances, Mappings Constraints

• Use Affordances, Mappings Constraints to
  evaluate interfaces and products.
• Use Affordances, Mappings Constraints to design
  interfaces and products.

31
Affordances

• Affordances refers to the perceived and actual
  properties of the thing that determine just how
  the thing could be used.
• The appearance of the thing tells you how to
  use it.

32
Mapping

• The relationship between two things, in most
  cases the mapping from digital world to real
  world.
• Metaphors and analogies.

33
Constraints

• Limitations on the product.
• Physical Constraints
• Those that limit our physical use of the product.
• Semantic Constraints
• Relies upon semantic meaning knowledge.
• Example automobiles windshield faces forward,
  therefore, you drive the car facing the
  windshield.

34
Constraints

• Logical Constraints
• There are the obvious, yet logical constraints.
• You cant see items outside of your screens view
  port.
• Cultural Constraints
• Things that are specific to the users culture.
• Example Americans drive on the opposite side of
  the road versus Europeans and West Indians.

35
Evaluating Interfaces

• Look for
• Affordances, Mappings Constraints
• Language
• Layout
• Color
• Tone Etiquette
• Special Considerations such as standards,
  disabilities, etc.

36
5 Human Factors Principles

• Language
• Layout
• Color
• Tone Etiquette
• Special Considerations such as standards,
  disabilities, etc.