IAT 334 Interface Design

1. IAT 334Interface Design Task Analysis ______________________________________________________________________________________SCHOOL OF INTERACTIVE ARTS + TECHNOLOGY [SIAT] | WWW.SIAT.SFU.CA IAT 334

2. Agenda • Task Analysis • Evaluation • Predictive evaluation • Heuristic evaluation • Discount usability testing • Cognitive walkthrough IAT 334

3. Task Conformance • Task coverage • Can system do all tasks of interest? • Task adequacy • Can user do tasks? • Does system match real-world tasks? IAT 334

4. Task Analysis • Analyzing how people do their jobs • Go to their environment • Learn about, analyze and describe their tasks • Examine users’ tasks to better understand what they need from interface and how they will use it IAT 334

5. Task Analysis • Gather data about what users need to do or accomplish …then… • Represent data for interpretation and use in design decisions IAT 334

6. Information to be Gathered • Information about users • Description of environment • where the tasks will be performed • Major goals of the job • what will result in a successful end state? • User preferences & needs • before they even start: coffee, pen, notebook, log sheets… IAT 334

7. Task Analysis • Broad Focus • Observe users of current system(s) • Generate requirements • Hierarchical task analysis • Knowledge-based task analysis • Entity-Relationship model IAT 334

8. Data Gathering Techniques • Observation • Interviews & Contextual Inquiry • Ethnography also… • Surveys & Questionnaires • Focus Groups & Expert Debriefing • Competitive Product Review • Documentation mining • Data logging IAT 334

9. Information to be Gathered • Tasks & Subtasks: • Physical • Cognitive • Communication • Conditions under which these tasks are done • Results/outcomes of tasks • Requirements to perform task: • Information • Communication with others • Equipment IAT 334

10. 1. Observation • Watch users do what they do • Typically from a distance • Record with videotape • May require coding video later • Take lots of notes, sketches • Focus on specific task-relevant behaviors in notes, but later convert to abstract subtasks IAT 334

11. 2. Interviews • Engage the user more than just watching • Structured interviews • Efficient, but requires training • Unstructured • Inefficient, but requires no training • Semi-structured • Good balance • Often appropriate IAT 334

12. Semi-Structured Interviews • Predetermine data of interest • Plan for effective question types • How do you perform task x? • Why do you perform task x? • What information do you need to…? • Who do you need to communicate with to…? • What do you use to…? • What happens after you…? • What is the result or consequence of NOT…? IAT 334

13. 3. Ethnography • Deeply contextual inquiry • “Wallow in the data” • “Live among” the users • Understanding the full complexity of behavior, in its complete social context • Note: Techniques based in sociology and anthropology--the study of humans IAT 334

14. Comment • Techniques 1-3 are similar, but differ in how “plugged in” or engaged the observer gets • There are Pros and Cons of all these techniques IAT 334

15. More! • Often used in addition: • Surveys & Questionnaires • Focus Groups & Expert Debriefing • Competitive Product Review • Documentation mining • Data logging IAT 334

16. Existing System • Usually task analysis involves an examination of an existing system, process or practice • Watch what they do and how they do it IAT 334

17. 4. Surveys & Questionnaires • Subjective answers in a quantitative format • What does this mean? • Questions: • Exploratory vs. confirmatory • Open-ended vs. categorical (exhaustive) • NB: If you ask it, use it. If you won’t/can’t use it, don’t ask it. IAT 334

18. Questionnaires • Likert scale common IAT 334

19. Typical Questions • Rank the importance of each of these tasks (give a list of tasks) • List the four most important tasks that you perform (this is an open question) • List the pieces of information you need to have before making a decision about X, in order of importance • Are there any other points you would like to make? (open-ended opinion question; good way to end) IAT 334

20. 5. Focus Groups • Structured Interview with groups of individuals • 3 to 10 persons • Use several different groups with different roles or perspectives • Manage the interaction • Avoid few people dominating the discussion • Focus on preferences and views, not performance • Relatively low cost, quick way to learn a lot • Audio or video record, with permission IAT 334

21. 6. Competitive Products • Looking for both good and bad ideas • Functionality • UI style • Why are they successful or unsuccessful? • What does successful really mean? • (Note: Successful does not equal usable) IAT 334

22. 7. Document Mining • Documentation • Often contains description of how the tasks should be done • Standards docs • Manuals • Histories • Best Practices IAT 334

23. 8. Data Logging • Automatically tracking: • Keystroke/mouse clicks • Timers • Logs of transactions • Physical location/movement trackers • Cell phones • GPS IAT 334

24. No Existing System • Gather documents, talk with knowledgeable people, etc. • Can still be useful to help generate requirements IAT 334

25. Task Analysis Focus • Not on internal cognitive state of user (more on that in the near future) • Focus on observable behaviors • Observe users, what they do, and how they do it • What are the practices, methods, steps, objects, …, used? IAT 334

26. Now that you have observed… • You have piles of notes, hours of video, surveys up to here… • How can you digest and represent the data, to turn it into information? IAT 334

27. Describe Tasks • Task Outlines • Narratives • Hierarchies & Network Diagrams • Hierarchical Task Analysis (HTA) • Entity-Relationship Diagrams • Flow Charts • Card Sorting IAT 334

28. 1. Task Outline Using a lawnmower to cut grass Step 1. Examine lawn • Make sure grass is dry • Look for objects laying in the grass Step 2. Inspect lawnmower • Check components for tightness • Check that grass bag handle is securely fastened to the grass bag support • Make sure grass bag connector is securely fastened to bag adaptor • Make sure that deck cover is in place • Check for any loose parts (such as oil caps) • Check to make sure blade is attached securely • Check engine oil level • Remove oil fill cap and dipstick • Wipe dipstick • Replace dipstick completely in lawnmower • Remove dipstick • Check that oil is past the level line on dipstick IAT 334

29. 2. Narratives • Describe tasks in sentences • Often expanded version of task outline • More effective for communicating general idea of task • Not effective for details • Not effective for branching tasks • Not effective for parallel tasks IAT 334

30. 3. Hierarchies & Networks • Hierarchical Task Analysis (HTA) • Graphical notation & decomposition of tasks • Tasks as sets of actions • Tasks organized into plans (describes sequence) • Network / Entity-Relationship Diagrams • Objects/people with links to related objects • Links described functionally and in terms of strength IAT 334

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32. Hierarchical Task Decomposition • Decompose task into • Subtasks • Multiple levels • Plans describing ordering and conditions IAT 334

33. Common Plans • Fixed sequence • Optional tasks • Waiting for events • Cycles • Time-sharing -- parallel • Discretionary IAT 334

34. Entity-Relationship • Object-based methodology, with a real stress on relationship between objects and actions • Involves • Concrete objects • Actors • Composite objects IAT 334

35. Example • Task: Develop design for final project • Objects - Pens, paper, drawing tools, etc. • Actors - Mary, Bob, Sally • Composite objects - The “team” IAT 334

36. 4. Flow Charts • Flow Chart of Task Steps • Combines Entity-relationship (network) with sequential flow, branching, parallel tasks. • Includes actions, decisions, logic, by all elements of the system • Abstracted • Mature, well-known, good tools IAT 334

37. 5. Knowledge-based Analysis • List all objects and actions involved in a task, then build a taxonomy of them • Often times, work with domain expert to get help IAT 334

38. Methodology • Sample: • Get 3x5 cards • Put different object/action on each • Don’t worry about repetition at this point! • Group into piles, subpiles, etc. IAT 334

39. Utility • This type of task analysis can be very useful when you’re writing a manual or some documentation • Taxonomy --- Document sections IAT 334

40. Methodology • Often list attributes, actions of objects Object: pen simple Attribute: color: red writing: on/off Object: Mary actor Actions: M1: make a sketch M2: organize meeting IAT 334

41. Use • Produce documentation • Training, manuals, tutorials • Requirements capture and system design • Helps you define requirements document • Helps decide what should be included • Helps interface design • Hierarchical breakdown might feed menu design IAT 334

42. Summary:Data Gathering Techniques • Observation • Interviews & Contextual Inquiry • Ethnography also… • Surveys & Questionnaires • Focus Groups & Expert Debriefing • Competitive Product Review • Documentation mining • Data logging IAT 334

43. Summary:Describe Tasks • Task Outlines • Narratives • Hierarchies & Network Diagrams • Hierarchical Task Analysis (HTA) • Entity-Relationship Diagrams • Flow Charts • Card Sorting IAT 334