IAT 334 Interface Design Task Analysis SCHOOL OF

IAT 334 Interface Design Task Analysis ___________________________________________ SCHOOL OF INTERACTIVE ARTS + TECHNOLOGY [SIAT] | WWW. SIAT. SFU. CA Jan 13, 2011 IAT 334 1

Agenda g Task Analysis g Evaluation g Predictive evaluation – Heuristic evaluation – Discount usability testing – Cognitive walkthrough Jan 13, 2011 IAT 334 2

Task Conformance g Task coverage – Can system do all tasks of interest? g Task adequacy – Can user do tasks? – Does system match real-world tasks? Jan 13, 2011 IAT 334 3

Task Analysis g Analyzing how people do their jobs – Go to their environment – Learn about, analyze and describe their tasks g Examine users’ tasks to better understand what they need from interface and how they will use it Jan 13, 2011 IAT 334 4

Task Analysis g Gather data about what users need to do or accomplish …then… g Represent data for interpretation and use in design decisions Jan 13, 2011 IAT 334 5

Information to be Gathered g Information about users g Description of environment – where the tasks will be performed g Major goals of the job – what will result in a successful end state? g User preferences & needs – before they even start: coffee, pen, notebook, log sheets… Jan 13, 2011 IAT 334 6

Task Analysis g Broad Focus g Observe users of current system(s) g Generate requirements – Hierarchical task analysis – Knowledge-based task analysis – Entity-Relationship model Jan 13, 2011 IAT 334 7

Data Gathering Techniques Observation 2. Interviews & Contextual Inquiry 3. Ethnography also… 4. Surveys & Questionnaires 5. Focus Groups & Expert Debriefing 6. Competitive Product Review 7. Documentation mining 8. Data logging 1. Jan 13, 2011 IAT 334 8

Information to be Gathered g Tasks & Subtasks: – Physical – Cognitive – Communication Conditions under which these tasks are done g Results/outcomes of tasks g Requirements to perform task: g – Information – Communication with others – Equipment Jan 13, 2011 IAT 334 9

1. Observation g Watch users do what they do – Typically from a distance g Record with videotape – May require coding video later g Take lots of notes, sketches g Focus on specific task-relevant behaviors in notes, but later convert to abstract subtasks Jan 13, 2011 IAT 334 10

2. Interviews g Engage the user more than just watching g Structured interviews – Efficient, but requires training g Unstructured – Inefficient, but requires no training g Semi-structured – Good balance – Often appropriate Jan 13, 2011 IAT 334 11

Semi-Structured Interviews Predetermine data of interest g Plan for effective question types g – – – – 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…? Jan 13, 2011 IAT 334 12

3. Ethnography g Deeply contextual inquiry – “Wallow in the data” g “Live among” the users g Understanding the full complexity of behavior, in its complete social context g Note: Techniques based in sociology and anthropology--the study of humans Jan 13, 2011 IAT 334 13

Comment g Techniques 1 -3 are similar, but differ in how “plugged in” or engaged the observer gets g There are Pros and Cons of all these techniques Jan 13, 2011 IAT 334 14

More! g Often used in addition: 4. 5. 6. 7. 8. Jan 13, 2011 Surveys & Questionnaires Focus Groups & Expert Debriefing Competitive Product Review Documentation mining Data logging IAT 334 15

Existing System g Usually task analysis involves an examination of an existing system, process or practice g Watch Jan 13, 2011 what they do and how they do it IAT 334 16

4. Surveys & Questionnaires g Subjective answers in a quantitative format – What does this mean? g 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. Jan 13, 2011 IAT 334 17

Questionnaires g Likert Jan 13, 2011 scale common IAT 334 18

Typical Questions Rank the importance of each of these tasks (give a list of tasks) g List the four most important tasks that you perform (this is an open question) g List the pieces of information you need to have before making a decision about X, in order of importance g Are there any other points you would like to make? (open-ended opinion question; good way to end) g Jan 13, 2011 IAT 334 19

5. Focus Groups g 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 g Relatively low cost, quick way to learn a lot g Audio or video record, with permission g Jan 13, 2011 IAT 334 20

6. Competitive Products g Looking for both good and bad ideas – Functionality – UI style g Why are they successful or unsuccessful? g What does successful really mean? – (Note: Successful does not equal usable) Jan 13, 2011 IAT 334 21

7. Document Mining g Documentation – Often contains description of how the tasks should be done – Standards docs – Manuals – Histories – Best Practices Jan 13, 2011 IAT 334 22

8. Data Logging g Automatically tracking: – Keystroke/mouse clicks – Timers – Logs of transactions – Physical location/movement trackers • Cell phones • GPS Jan 13, 2011 IAT 334 23

No Existing System g Gather documents, talk with knowledgeable people, etc. g Can still be useful to help generate requirements Jan 13, 2011 IAT 334 24

Task Analysis Focus g Not on internal cognitive state of user (more on that in the near future) g Focus on observable behaviors – Observe users, what they do, and how they do it – What are the practices, methods, steps, objects, …, used? Jan 13, 2011 IAT 334 25

Now that you have observed… g You have piles of notes, hours of video, surveys up to here… g How can you digest and represent the data, to turn it into information? Jan 13, 2011 IAT 334 26

Describe Tasks 1. 2. 3. Task Outlines Narratives Hierarchies & Network Diagrams – Hierarchical Task Analysis (HTA) – Entity-Relationship Diagrams 4. 5. Flow Charts Card Sorting Jan 13, 2011 IAT 334 27

1. Task Outline Using a lawnmower to cut grass Step 1. Examine lawn a. Make sure grass is dry b. Look for objects laying in the grass Step 2. Inspect lawnmower a. Check components for tightness 1) 2) 3) 4) 5) 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 b. Check engine oil level 1) 2) 3) 4) 5) Jan 13, 2011 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 28

2. Narratives g Describe tasks in sentences g Often expanded version of task outline g More effective for communicating general idea of task g Not effective for details g Not effective for branching tasks g Not effective for parallel tasks Jan 13, 2011 IAT 334 29

3. Hierarchies & Networks g Hierarchical Task Analysis (HTA) – Graphical notation & decomposition of tasks – Tasks as sets of actions – Tasks organized into plans (describes sequence) g Network / Entity-Relationship Diagrams – Objects/people with links to related objects – Links described functionally and in terms of strength Jan 13, 2011 IAT 334 30

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Hierarchical Task Decomposition g Decompose task into – Subtasks • Multiple levels – Plans describing ordering and conditions Jan 13, 2011 IAT 334 32

Common Plans g Fixed sequence g Optional tasks g Waiting for events g Cycles g Time-sharing -- parallel g Discretionary Jan 13, 2011 IAT 334 33

Entity-Relationship g Object-based methodology, with a real stress on relationship between objects and actions g Involves – Concrete objects – Actors – Composite objects Jan 13, 2011 IAT 334 34

Example g Task: Develop design for final project – Objects - Pens, paper, drawing tools, etc. – Actors - Mary, Bob, Sally – Composite objects - The “team” Jan 13, 2011 IAT 334 35

4. Flow Charts g 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 Jan 13, 2011 IAT 334 36

5. Knowledge-based Analysis g List all objects and actions involved in a task, then build a taxonomy of them g Often times, work with domain expert to get help Jan 13, 2011 IAT 334 37

Methodology g Sample: – Get 3 x 5 cards – Put different object/action on each – Don’t worry about repetition at this point! – Group into piles, subpiles, etc. Jan 13, 2011 IAT 334 38

Utility g This type of task analysis can be very useful when you’re writing a manual or some documentation – Taxonomy --- Document sections Jan 13, 2011 IAT 334 39

Methodology g Often list attributes, actions of objects Object: pen simple Attribute: color: red writing: on/off Object: Mary actor Actions: M 1: make a sketch M 2: organize meeting Jan 13, 2011 IAT 334 40

Use g Produce documentation – Training, manuals, tutorials g Requirements capture and system design – Helps you define requirements document – Helps decide what should be included g Helps interface design – Hierarchical breakdown might feed menu design Jan 13, 2011 IAT 334 41

Summary: Data Gathering Techniques Observation 2. Interviews & Contextual Inquiry 3. Ethnography also… 4. Surveys & Questionnaires 5. Focus Groups & Expert Debriefing 6. Competitive Product Review 7. Documentation mining 8. Data logging 1. Jan 13, 2011 IAT 334 42

Summary: Describe Tasks 1. 2. 3. Task Outlines Narratives Hierarchies & Network Diagrams – Hierarchical Task Analysis (HTA) – Entity-Relationship Diagrams 4. 5. Flow Charts Card Sorting Jan 13, 2011 IAT 334 43