1. Requirements and Task Analysis

2. Why are requirements important?
To understand what we are going to be doing
We build systems for others, not for ourselves
Requirements definition: the stage where failure occurs most commonly
Getting requirements right is crucial

3. Functional vs. NonFunctional
Historically requirements
Features, functions that the system should do
Properties of the overall system
“-ilities” (quality, evolveability, flexibility, etc.)
Environment
User requirements
Usability requirements
Requirements definition: the stage where failure occurs most commonly
Getting requirements right is crucial

4. Not just “requirements”
Overall goals, success criteria
User characteristics
Task analysis
Environment – physical, social, technical
Constraints
Usability goals, criteria

5. (Not All) Requirements Gathering Methods
1. Observation
2. Thinking Out Loud & Cooperative Evaluation
3. Interviews
4. Questionnaires
5. Focus groups
6. Study Documentation
7. Look at competitive products
Ethnography is emphasis here.
Jeff - please say somemore about 2 and 3 and more about diff with 1

6. Know Thy User You want to know Who your users are What they are doing
When they are doing it
Why they are doing it
What tools they are using
How they are using them

7. Human Characteristics
Physical attributes (age, gender, size, reach, visual angles, etc…)
Perceptual abilities (hearing, vision, heat sensitivity…)
Cognitive abilities (memory span, reading level, musical training, math…)
Personality and social traits (likes, dislikes, preferences, patience…)
Cultural and international diversity (languages, dialog box flow, symbols…)
Special populations, (dis)abilities

8. User Characteristics
Attitude, morale, willingness to change, motivation, reading level, typing skill, education, frequency of use, training, color-blindness, handedness, gender,…
Novice, intermediate, expert
System experience, task experience, computer literacy
Cultural factors
Uses of icons, colors, words, metaphors

9. Design implications Consider the implications: Fact Implications
Users yrs
Range of text sizes
Range of grip strength
Some French speakers
Multilingual interface
Astronaut users
Extensive training available
Military context
Aesthetics less of an issue
Ruggedness is critical

10. Are Cultural Differences Important?
Anna: the IKEA agent
Designed to be different for UK and US customers
What are the differences and which is which?
What should Anna’s appearance be like for other countries, like India, South Africa, or China?

11. Persona: describing users
Description of a user and what the user wishes to do
Put a specific human face on abstract data
Be specific/detailed, even give names and picture
Easier to remember and talk about
Two personas for ATM usage follow
Adapted from User Interface Design and Evaluation, The Open University
Developed by Cooper (1999)

12. Sandra (representing young adults thru middle age)
Sandra is 30, is married to Jason, has two children Todd(6) and Carly (18 months). They live in a subdivision that is about three miles from the town center, where the bank and stores are located. Jason uses the car for work, and works long hours, leaving at 6:45 am and returning at 8:00 pm. Sandra does not drive, so has to use public transportation. She tries to run errands and shop while Todd is in school, so she only has to take Carly to town with her. She typically needs to make two trips to town each week to get everything done. She uses a stroller with Carly, and the bank is one flight up via escalator, so she prefers to use the ATM outside the first floor, even though there is no canopy to protect customers from bad weather.

13. Grandpa Marvin (representing middle age to senior citizens)
Marvin is 68 years old, and his social security is deposited into his bank account at the start of each month. He goes to the bank every week, withdrawing enough cash for the week - for miscellaneous expenditures. Regular bills are paid by check. He stands in line for a live teller, as he prefers the social interaction to using an ATM, even though his new artificial hip makes standing in line uncomfortable. He does not have an ATM card.

14. Task Analysis
Process of analyzing and documenting how people perform their jobs or activities
Task-subtask decomposition
Focus on:
Activities
Artifacts
Relations
More in a moment…

15. Physical Environment Amount of space to work
Lighting levels / directions
Noise level
Temperature, humidity, dust…
Standing / sitting
Power availability
Dangers
Implications?

16. Technical Environment
Computers/platforms for application
Technology to interact with
Networking
Mobility
Implications?

17. Social Environment How do users interact? Roles?
How do users interact with others?
Social implications of problem or solution?
Interruption
Privacy
Implications?

18. Stakeholders Primary – targeted end users
Secondary – receive output or provide input to system
Tertiary – others directly receiving benefits from system success or failure
Facilitating – design, development, maintenance

19. Stakeholder analysis Cell phone Bus stop kiosk
Nuclear power plant control system

20. Typical Real-World Constraints
Elapsed time to market
Cost/effort to design and implement
Size/footprint/weight/power/price
Computer power/memory (related to cost and power
Consistency with overall product line
Backward compatibility
Differentiation from competitive products

21. Usability Requirements
Usability goals: such as learnability, consistency, robustness, etc.
Ways to measure and judge success
Time to complete key tasks - min, max
Time to become proficient - do given set of tasks in given time
Subjective satisfaction

22. Example
What factors (environmental, user, usability) would affect the following systems?
Self-service filling and payment system for a gas station
On-board ship data analysis system for geologists searching for oil
Fashion website for buying clothes

23. Example: movie ticket kiosk
List a few user characteristics
Create one persona
List a few important environmental considerations
List a couple other real world constraints

24. (Not All) Requirements Gathering Methods
Observation
Thing out Loud & Cooperative Evaluation
Interviews
Questionnaires
Focus groups
Study Documentation
Look at competitive products
Ethnography
Contextual Inquiry
Ethnography is emphasis here.
Jeff - please say somemore about 2 and 3 and more about diff with 1

25. Formative vs. Summative evaluation
assess an existing system
judge if it meets some criteria
Formative
assess a system being designed
gather input to inform design
Summative or formative?
Depends on
maturity of system
how evaluation results will be used
Same technique can be used for either

26. Observation Watch user(s) doing activity of interest to you
“Think out loud” or “Think aloud”
encourage user to verbalize what they are thinking
Cooperative or participative evaluation
Relaxed version of think-aloud
Evaluator and user talk to each other
Why are you doing that?
How did you know the result was what you wanted?
Are there other ways to achieve the same goal?
How did you decide to do things this way?

27. Observing Tips
Carefully observe everything about users and their environment
Think of describing it to someone who has never seen this activity before
What users say is important, so are non-verbal details

28. Interview Users Semi-structured: predetermine sets of questions
But can expand upon them as needed
Example question types
How do you perform task x?
Why do you perform task x?
Under what conditions do you perform task x?
What do you do before you perform…?
What information do you need to…?
Whom do you need to communicate with to …?
What do you use to…?
What happens after you…?
What is the result or consequence of…?
What is the result or consequence of NOT…?
See DFAB for more tips and discussion

29. Focus Groups Interview groups of users – 3 to 10 at a time
Use several different groups with different roles or perspectives
Relatively low cost, quick way to learn a lot
Use structured set of questions
More specific at beginning, more open as progresses
Allow digressions before coming back on track
More challenging to lead than single interview
Some people quiet, some dominating
Easier to get off track

30. Questionnaires (or Surveys)
Easier to give to broader audience
Shorter, more focused than interview
General criteria
Make questions clear and specific
Ask some closed questions with range of answers
Sometimes also have a no opinion option, or other answer option
Do test run with one or two people

31. Some Example 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)
Numerical scales:
On a scale of 1 to 7, how comfortable are you…
Or words: Strongly agree, agree, neutral, disagree, strongly disagree

32. Example: movie kiosk What to observe? How?
Who to interview? What questions?
Who to give questionnaire to? What questions?
What about focus group?
What are differences between methods?

33. Study Documentation Quick and easy if it exists
Often describe how things should be done rather than how they are done
Try to understand why not done “by the book”
Alternative: interview a domain expert

34. Look at Competitive Products
Looking for both good and bad ideas
Functionality
UI style
Possibly do user task performance metrics to establish bounds on your system

35. Ethnography Deeply contextual study
Immerse oneself in situation you want to learn about (has anthropological and sociological roots)
Observing people in their cultural context
Behavior is meaningful only in context
For UI designers: understand current methods, activities, environment, problems to aid design
Observation + interviews

36. Ethnography Things of interest to evaluator
Structure and language used in work
Individual and group actions
Culture affecting work
Explicit and implicit aspects of work
Example: Office work environment
Business practices, rooms, artifacts, work standards, relationships between workers, managers, …

37. Drawbacks of Ethnographic Methods
Time required
Can take weeks or months for large systems
Scale
Most use small numbers of participants just to keep somewhat manageable
Type of results
Highly qualitative, may be difficult to present/use
Acquired skill – “learn by doing”
Identifying and extracting “interesting” things is challenging

38. Contextual Inquiry
Practical ethnographic-inspired method for requirements
Master-apprentice relationship
Watch and talk to customer as they do their work
Designer looking for details and structure of work that will influence design
Contextual interview + observation

39. Contextual Inquiry Principles
Gather information close to real situation
Avoids abstractions and summarization
Partnership
Designers help customers see and talk about structure through probing
Share design ideas in the moment
Interpretation
Designer must turn observations into useful design implications
Share this reasoning with customer to get feedback
Focus
Designer must focus on aspects of work that will be useful
For more info: see Beyer and Holtzblatt. Contextual Design. Morgan Kaufmann.

40. Contextual Inquiry How compares with other methods?
Advantages?
Disadvantages?
In what situations would it be useful?
When might it not be useful?

41. Which Methods to Use?
Self-service filling and payment system for a gas station
On-board ship data analysis system for geologists searching for oil
Fashion website for buying clothes at large department store

42. Making Sense Organize and categorize responses, comments, observations
“coding scheme”
Card Sorting
Affinity Diagrams
Task analysis

43. Affinity Diagram - “Sorted Cards”
From Interaction Design, Preece Rogers and Sharp

44. Task Analysis Focus on observable behaviors
What are the practices, methods, steps, objects, …, used?
Tasks & Subtasks
Physical
Cognitive
Communication
Conditions under which these tasks are done
Results/outcomes of tasks
Requirements to perform task
Information, artifacts
Communication with others
Equipment
Also see: Hackos and Redish, User and Task Analysis for Interface Design. Wiley Publishing.

45. Describing activities
Scenarios
Use Cases
Task - subtask decomposition
Includes sequencing information
Workflow diagrams
Flow charts
ER or object models

46. Scenario Describe tasks and context in sentences
Natural way of describing general idea
Good for demonstrating specific problems, reasons behind actions, atypical activities
Bad for representing branching, parallel activities, various possibilities of one activity

47. Scenario: Example 1
Its Friday afternoon and John just got paid. He wants to deposit his check immediately so he can pay his rent. He stops at one branch of his bank on the way home from work. He waits in his car while another person finishes using the ATM in front of the bank since it is drizzling outside. He walks up to the ATM to deposit his check. Only, as he is about to put the check into the envelope at the ATM, he realizes that he has not signed the back of it, and he has no pen and can not find one on or near the ATM machine. He cancels the transaction on the ATM, and enters the bank, which luckily is still open for 5 more minutes. He goes to the counter, finds a pen, and signs his check. He also fills out a deposit slip. He then waits to see a teller in person to deposit his check, and get money for the weekend.

48. Scenario: Example 2
Annie walks up to the ATM to deposit her weekly pay check. She puts her ATM card into the slot in the machine. She then enters her PIN number quickly, trying to block the person waiting behind her from viewing the keypad, and knows that she does not have to press “Enter” at this particular machine. She then chooses “Deposit” and “Check.” She enters the amount of the check using the keypad, then takes an envelope from the ATM machine, puts her check inside, seals the envelope and writes the amount of the check on the outside. She feeds the envelope into the slot into the ATM machine. She then selects “No other transactions” to finish, and waits to receive her receipt and ATM card.

49. Use Case Description of a user’s goal in using a system
Focuses on user-system interaction
One path through a use case is sometimes called a scenario
Often presented as a series of steps
Diagram of actors and use cases

50. Use Case Diagram

51. Use Case example Arrange Meeting
1. The user chooses the option to arrange a meeting.
2. The system prompts user for the names of attendees.
3. The user types in a list of names.
4. The system checks that the list is valid.
5. The system prompts the user for meeting constraints.
6. The user types in meeting constraints.
7. The system searches the calendars for a date that satisfies the constraints.
8. The system displays a list of potential dates.
9. The user chooses one of the dates.
10. The system writes the meeting into the calendar.
11. The system s all the meeting participants informing them of them appointment

52. Hierarchical Task Analysis (HTA)
Graphical notation & decomposition of tasks
Goals – what the user wants to achieve
Tasks – do these to achieve the goals
Not necessarily computer related
Sequential dependencies
Multiple occurrences of tasks
Subtasks – lower-level tasks
Tasks organized into plans
Clusters of subtasks with a preferred order and prerequisite conditions

53. Task Model - Borrow Book
Sequences added as annotations
Can also show hierarchy as indented text
Goal
Tasks to
complete goal
Subtasks to
carry out
one task
From Interaction Design, Preece Rogers and Sharp

54. HTA: Types of Plans Fixed sequence Optional tasks Waiting events
Cycles
Time-sharing
Discretionary

55. HTA

56. Example
Goal: register for class

57. Flow Charts Flow Chart of Task Steps Complete, can become complex
Sequential flow, branching, parallel tasks.
Includes actions, decisions, logic, by all elements of the system
Mature, well-known, good tools for doing it

58. Flow Chart Example Start Continue? Document Manual Operation Y N Input
Display
End

59. Workflow Documents going from one person/organization to another
Multiple participants in an activity

60. Workflow Example - Document Flow
Create Travel
Request
(Traveler)
Ensure Funds
Available
(Accounting)
Approval
(Dean)
Notification of
Approval
(Dean)
No Funds
Notification of
Approval
(Dean)
Make Trip
(Traveler)
Complete
Expense Report
(Traveler)
Approval
(Accounting)
Etc

61. From Interaction Design, Preece Rogers and Sharp

62. Entity Relationship Diagrams
Object Oriented Models
Objects/people with links to related objects
Stress relationship between objects and actions
Links described functionally and in terms of strength
About relations, not procedures
Complements HTA & flow charts

63. Object Model: ATM Objects Relations Actions on objects Etc
Account, ATM machine, ATM card, customer
Relations
Customer has one or more accounts
ATM machine accesses account
Actions on objects
Account: deposit($), withdraw($), balance
ATM machine: authenticate, dispense($), print receipt
Etc

64. Example
Create a scenario describing a CURRENT movie ticket buying activity – typical
Create a scenario describing a CURRENT movie ticket buying activity – atypical or problem
Create an HTA describing the basic movie buying activity
What might you describe with an E-R or object diagram?
What might you describe with a workflow or flowchart?

65. Beyond Requirements Task analysis throughout life cycle:
Describe and document design ideas
Help design menu, dialog structure
Help create documentation and help
Task descriptions can be given at any necessary abstraction level

66. Summary Determine what data you need
Gather it using various appropriate methods and techniques
Represent the users, environment, tasks and subtasks, plus other related information
Use this data as basis for design
Note: Be efficient!