1. CSC 341 Human-Computer Interaction
Lecture Slides by
Dr. Mai Elshehaly

2. Today’s Class Evaluation Formative versus summative Paradigms
From tasks to requirements (recap)
Predictive models: Fitts’ Law (recap)
Evaluation
Formative versus summative
Paradigms
Techniques
Heuristic Evaluation
Gestalt Theory
DECIDE Framework

3. From User Tasks to Requirements (a recap)
“A functional requirement relates directly to a process the system has to perform as a part of supporting a user task and/or information it needs to provide as the user is performing a task.”
Dennis, A., Wixom, B. H., & Tegarden, D. (2015). Systems analysis and design: An object-oriented approach with UML. John Wiley & Sons.

4. From User Tasks to Requirements (a recap)
The International Institute of Business Analysis (IIBA) defines functional requirements as:
“the product capabilities, or things that a product must do for its users.”
Functional requirements define how the system will support the user in completing a task.
Dennis, A., Wixom, B. H., & Tegarden, D. (2015). Systems analysis and design: An object-oriented approach with UML. John Wiley & Sons.

5. From User Tasks to Requirements (a recap)
For example, assume the user task is:
T1: Schedule a client appointment.
The functional requirements associated with that task include:
Determine client availability
Find available openings matching client availability
Select desired appointment
Record appointment
Confirm appointment.
Notice how these functional requirements expand upon the user's task to describe capabilities and functions that the system will need to include, allowing the user to complete the task.
Dennis, A., Wixom, B. H., & Tegarden, D. (2015). Systems analysis and design: An object-oriented approach with UML. John Wiley & Sons.

6. What is formative evaluation?

7. What is formative evaluation?

8. Notice some interesting keywords?
What is evaluation?
“The process of systematically collecting data that informs us about what it is like for a particular user or group of users to use a product for a particular task in a certain type of environment.” [Chapter 10]
Notice some interesting keywords?

9. What is evaluation?
“The process of systematically collecting data that informs us about what it is like for a particular user or group of users to use a product for a particular task in a certain type of environment.” [Chapter 10]

10. Why evaluate?
The goal of evaluation is to assess how well a design fulfills users' needs and whether users like it.

11. When to evaluate?
Formative: Evaluations done during design to check that the product continues to meet users' needs
Summative: Evaluations done to assess the success of a finished product, such as those to satisfy a sponsoring agency or to check that a standard is being upheld

12. Why formatively evaluate?
The goal of formative evaluation is to assess how well a design fulfills users' needs and whether users like it, during the design and implementation phases, not after.
Developers Identify what to focus on at different stages of development
Designers Understand requirements: this tends to happen by a process of negotiation between designers and users
Users Understand design alternatives and are able to give better feedback

13. How to Evaluate?
Evaluation Paradigms
Evaluation Techniques

14. Evaluation Paradigms
How people from the discipline think about evaluation
Evaluation is guided by a set of beliefs that may also be underpinned by theory.
These beliefs and the evaluation techniques associated with them are known as an evaluation paradigm

15. Predictive Evaluation
Evaluation Paradigms
Quick and Dirty
Informal meetings
Solicit feedback from users or consultants to confirm that their ideas are in line with users' needs and are liked
Data: descriptive sketches, notes, etc.
Usability Testing
Measuring users performance on controlled (but typical) tasks
Users are recorded and logged
Performance: error and time
Opinions: questionnaires and interviews
Field Studies
In a natural setting through observation, interviews, ethnography
Data: audio, video, notes
Analysis: content, discourse, and conversational
Evaluator: insider or outsider
Predictive Evaluation
Experts apply their knowledge of typical users, using heuristics
Use of theoretical models (e.g. usability goals, interaction models, etc.)

16. Heuristic Evaluation A group of experts perform a walkthrough
Each inspector browses through each part of interaction design
asking (to self) the heuristic questions
Assessing compliance
noting where heuristics are supported and where violated, along with context (e.g., screenshots)
Inspectors get together as a team
Discuss, compare, and merge problem lists
Brainstorm suggested solutions
Decide on recommendations
Write report
Most widely used HCI heuristics are Nielsen’s heuristics

17. Nielsen’s 10 usability heuristics

18. 1. visibility of system status
What mode am I in now?
What did I select?
How is the system interpreting my actions?

19. 2. Match between system and real-world
Speak the user’s language
Information shown in logical order
Avoid technical jargon

20. 3. User Control and freedom
Users will make mistakes and want to fix or exit away from them

21. 4. Consistency and Standards

22. 5. Error Prevention
Only legal data and legal commands are allowed

23. Bonus Activity ( +2 points)
Explain in your Project Phase II deliverable which of Nielsen’s heuristics are upheld and which are violated ( you will be rewarded for acknowledging violations)
Refer to heuristic-evaluation-for-usability-in-hci-and-information-visualization

24. Gestalt Theory
From the German language, Gestalt stands for configuration
According to Gestalt psychologists, there are five main laws of groupings that we can apply to heuristics evaluations:
Proximity
Similarity
Continuity
Closure
Common Fate

25. Proximity
Dr Ayman Ezzat modified version of Dr, Frank Kriwaczek

26. Dr Ayman Ezzat modified version of Dr, Frank Kriwaczek

27. Dr Ayman Ezzat modified version of Dr, Frank Kriwaczek

28. Dr Ayman Ezzat modified version of Dr, Frank Kriwaczek

29. Dr Ayman Ezzat modified version of Dr, Frank Kriwaczek

30. Dr Ayman Ezzat modified version of Dr, Frank Kriwaczek

31. Dr Ayman Ezzat modified version of Dr, Frank Kriwaczek

32. Dr Ayman Ezzat modified version of Dr, Frank Kriwaczek

33. Dr Ayman Ezzat modified version of Dr, Frank Kriwaczek

34. Dr Ayman Ezzat modified version of Dr, Frank Kriwaczek

35. Example Workflow

38. Break

39. DECIDE: A framework for evaluation

40. Evaluation Goals?

41. Suggest a technique and paradigm
Evaluation Goals
G1: Check that the evaluators have understood the users' needs.
Suggest a technique and paradigm

43. Suggest a technique and paradigm
Evaluation Goals
G2: Identify the metaphor on which to base the design.
Suggest a technique and paradigm

45. Suggest a technique and paradigm
Evaluation Goals
G3: Check to ensure that the final interface is consistent.
Suggest a technique and paradigm

47. Suggest a technique and paradigm
Evaluation Goals
G4: Investigate the degree to which technology influences working practices.
Suggest a technique and paradigm

49. Suggest a technique and paradigm
Evaluation Goals
G4: Identify how the interface of an existing product could be engineered to improve its usability
Suggest a technique and paradigm

51. DECIDE: A framework for evaluation

52. Evaluation Questions:
Break Goals into questions
Questions into sub-questions
Example:
Goal: Assess whether an online reservation system influences people’s dining out patterns

53. Evaluation Questions Example:
Goal: Assess whether an online reservation system influences people’s dining
Questions:
Is the user interface good/poor?
Is the system easy/difficult to navigate?
Is the search tool confusing?
Is the interface design inconsistent?
Is response time too slow?
Is the feedback confusing or maybe insufficient?

54. DECIDE: A framework for evaluation

55. DECIDE: A framework for evaluation

56. Practical Issues for Evaluation
Recruiting Users
Facilities and equipment
Budget and schedule
Expertise

57. DECIDE: A framework for evaluation

58. Ethical Issues Inform of procedures Explain confidentiality
Reassure (ability to stop at any time)
Pay users
Maintain confidentiality
Ask for permission to quote users if needed
Consent form
Activities to familiarize users

59. References
Chapter 10
Sections 11.1, 11.2, 11.3, 13.4

60. Quiz
Why can a Macintosh pull-down menu be accessed at least five times faster than a typical Windows pull-down menu.
Suggest at least two reasons why Microsoft made such an apparently stupid decision.

61. Quiz
Explain why a Macintosh pull-down menu can be accessed at least five times faster than a typical Windows pull-down menu.
Microsoft, Sun, and others have made the decision to mount the menu bar on the window, rather than at the top of the display, as Apple did.
They made this decision for at least two reasons:
Apple claimed copyright and patent rights on the Apple menu bar
Everyone else assumed that moving the menu bar closer to the user, by putting it at the top of the window, would speed things up.
More questions:
Test yourself:

62. Fitts’ Law (a recap) Fitts' Law
The time to acquire a target is a function of the distance A to and size W of the target.
Homework Assignment 2