1. Chapter 10 Identifying needs and establishing requirements

2. Outline What, How, and Why? What are requirements? Data gathering for requirements Data analysis, interpretation, and presentation Task description Task analysis

3. What, how, and why

4. What are we trying to achieve in the requirements activity? Two aims 1) to identify needs -> to understand as much as possible about the users, their work, and the context of that work 2) to establish requirements -> to produce a set of stable requirements that form a sound basis to move forward into thinking about design

5. How can we achieve this? The process seems sequential 1) Gather some data 2) Analyze and interpret the data 3) Extract some requirements from the data But, actually, the activities influence one another as the process iterates

6. Why bother? The importance of getting it right Many research works have reported the significant cost of fixing errors late in the software development lifecycle rather than early, during the requirements activity

8. What are requirements?

9. Requirement A requirement is a statement about an intended product that satisfies what it should do or how it should perform One of the aims of the requirements activity is to make the requirements as specific, unambiguous, and clear as possible, and that how to tell when they have been fulfilled

10. Different kinds of requirements Functional requirements Data requirements Environmental requirements User characteristics Usability goals and user experience goals

11. Functional requirements Capture what the product should do Example: a robot working in a car assembly plant Functional requirement: the robot should be able to accurately place and weld together the correct pieces of metal

12. Data requirements Capture the type, volatility, size/amount, persistence, accuracy, and value of the required data Example: in the personal banking domain Data must be accurate, must persist over many months and probably years, is very valuable, and there is likely to be a lot of it

13. Environmental requirements Context of use – circumstances in which the interactive products will be expected to operate Physical environment Social environment Organizational environment Technical environment

14. Physical environment Amount of light, noise, dust expected in the operational environment Will users need to wear protective clothing, such as large gloves or headgear, that might affect the choice of interface type? How crowded is the environment? e.g. speech interface may not be appropriate to be used in a public space

15. Social environment Will data need to be shared? Synchronous vs. asynchronous Do collaborators have to communicate across great distances?

16. Organizational environment How good is user support likely to be? How easily can it be obtained? Are there facilities or resources for training? How efficient or stable is the communications infrastructure? How hierarchical is the management?

17. Technical environment What technologies will the product run on or need to be compatible with? What technological limitations might be relevant?

18. Underwater PCs

19. User characteristics User’ s abilities User’ s skills Novice, Expert, Casual or Frequent user User’s nationality Educational background Preferences Personal circumstances Physical or mental disabilities

20. User characteristics User profile: a collection of attributes for a ‘typical user’ Personas: rich descriptions of typical users of the product synthesized from a number of real users each persona has a unique set of goals include a description of the pretend user’s skills, attitudes, tasks, and environment a name, a photograph, some personal details user experience goals

21. Data gathering for requirements

22. Data gathering Interviews explore issues involve users Focus group gain a consensus view highlight areas of conflicts and disagreement help stakeholders to meet designers and each other

23. Data gathering Questionnaires get initial responses to choose people to interview get a wider perspective on particular issues Direct observation understand the nature of the tasks and the context in which they are performed Indirect observation Use less often in requirements activity Good for logging current tasks

24. Data gathering Studying documentation good source of data about the steps involved in an activity, and any regulations governing a task good for understanding legislation and getting some background information on the work doesn’t involve stakeholder time Researching similar products

25. Data gathering Contextual inquiry Follows an apprenticeship model (user is expert, designer is apprentice) A combination of observation, discussion, and reconstruction of past events Four main principles Context (going to the workplace and seeing what happens) Partnership (user and developer collaborate) Interpretation (between the user and the developer) Focus (on the goals)

26. Problems with data gathering (1) Identifying and involving stakeholders: users, managers, developers, customer reps?, union reps?, shareholders? Involving stakeholders: workshops, interviews, workplace studies, co-opt stakeholders onto the development team ‘Real’ users, not managers: traditionally a problem in software engineering, but better now From: www.id-book.com

27. Problems with data gathering (2) Requirements management: version control, ownership Communication between parties: — within development team — with customer/user — between users… different parts of an organisation use different terminology Domain knowledge distributed and implicit: — difficult to dig up and understand — knowledge articulation: how do you walk? Availability of key people From: www.id-book.com

28. Problems with data gathering (3) Political problems within the organisation Dominance of certain stakeholders Economic and business environment changes Balancing functional and usability demands From: www.id-book.com

29. Data gathering guidelines for requirements Focus on identifying the stakeholders’ needs Involve all the stakeholder groups Involve more than one representative from each stakeholder group Support the data gathering sessions with suitable props, e.g. task descriptions and prototypes

30. Data interpretation and analysis Start soon after data gathering session Initial interpretation before deeper analysis Different approaches emphasize different elements e.g. class diagrams for object-oriented systems, entity-relationship diagrams for data intensive systems From: www.id-book.com

31. Brainstorming for innovation Include participants from a wide range of disciplines, with a broad range of experience Don’t ban ‘silly stuff’ Use catalysts for further inspiration Build one idea on top of another Jump back to an earlier idea Consider alternative interpretations

32. Brainstorming for innovation Keep records Start the brainstorm with a well-honed problem Use warm-up exercises, e.g. word games, exploration of physical items related or unrelated to the problem

33. Task description

34. Scenarios Use cases Essential use cases

35. Scenarios Informal narrative description Describes human activities or tasks in a story that allows exploration and discussion of contexts, needs, and requirements Does not describe the use of software or other technological support to achieve a task Use user’s vocabulary and phrasing

36. Scenarios Help to understand what people do now So, help to explore constraints, contexts, irritations, facilitators, etc. Help to identify stakeholders and products involved in the activity It is a good idea to emphasize the context, the usability and user experience goals, and the tasks the user is performing

37. Scenarios Inclusion of emotional elements helps to increase developers’ understanding of context Often, they are generated during workshop, interview, or brainstorming sessions to help explain or discuss users’ goals Can be used to imagine potential uses of a product and to capture existing behavior

38. Scenarios Not intended to capture a full set of requirements Are very personalized account, offering only one perspective

39. Scenario for holiday planner “The Thomson family enjoy outdoor activity holidays and want to try their hand at sailing this year. There are four members of the family: Sky who is 10 years old, Eamonn who is 15 years old, Claire who is 35, and Will who is 40. While out on a shopping trip they call by at the travel agents in their local town to start exploring the possibilities... The travel organizer is located in a quiet corner of the agents’ office, where there are comfortable seats and play things for young children. They all gather around the organizer and enter their initial set of requirements—a sailing holiday for four novices. The stand-alone console is designed so that all members of the family can interact easily and comfortably with it. The system’s initial suggestion is that they should consider a flotilla holiday, where several novice crews go sailing together and provide mutual support for first-time sailors…”

40. Use cases Focus on user goals, but the emphasis here is on a user-system interaction rather than the user’s task itself Describes ‘normal course’, i.e., the set of actions that the analyst believes to be most commonly performed Alternative courses are listed at the bottom of the use case

41. Use cases More formal than scenarios More useful at conceptual design stage than during requirements or data gathering But use cases have been found to help some stakeholders express their views on how existing systems are used and how a new system might work

42. Use cases To develop a use case, identify actors (people or system) actors’ goals or goals in using the system

43. Use case for holiday planner 1. The system displays options for investigating visa and vaccination requirements. 2. The user chooses the option to find out about visa requirements. 3. The system prompts user for the name of the destination country. 4. The user enters the country’s name. 5. The system checks that the country is valid. 6. The system prompts the user for her nationality. 7. The user enters her nationality. 8. The system checks the visa requirements of the entered country for a passport holder of her nationality. 9. The system displays the visa requirements. 10. The system displays the option to print out the visa requirements. 11. The user chooses to print the requirements.

44. Alternative courses for holiday planner Some alternative courses: 6. If the country name is invalid: 6.1 The system displays an error message. 6.2 The system returns to step 3. 8. If the nationality is invalid: 8.1 The system displays an error message. 8.2 The system returns to step 6. 9. If no information about visa requirements is found: 9.1 The system displays a suitable message. 9.2 The system returns to step 1.

45. Example use case diagram for holiday planner Holidaymaker Travel agent Update holiday details Identify potential Holiday options Retrieve visa requirements Retrieve vaccination requirements From: www.id-book.com

46. Essential use cases Represent abstractions from scenarios, i.e. they represent a more general case than a scenario embodies Try to avoid the assumptions of a traditional use case, i.e. there is a piece of technology to interact with, and assumptions about the user interface and the kind of interaction to be designed

47. Essential use cases Is a structured narrative consisting of three parts A name that expresses the overall user intention A stepped description of user actions A stepped description of system responsibility Instead of actors, essential use cases are associated with user roles

48. Example essential use case for holiday planner retrieveVisa USER INTENTIONSYSTEM RESPONSIBILITY find visa requirements request destination and nationality supply required information obtain appropriate visa info obtain copy of visa info offer info in different formats choose suitable format provide info in chosen format From: www.id-book.com

49. Task analysis

50. Used mainly to investigate an existing situation, not to envision new products What are they trying to achieve, why are they trying to achieve it, and how are they going about it? Examples: Hierarchical Task Analysis (HTA) Goals, Operations, Methods, and Selection rules (GOMS)

51. Hierarchical task analysis Involves breaking a task down into subtasks, then sub-sub-tasks and so on. These are grouped as plans which specify how the tasks might be performed in practice HTA focuses on physical and observable actions, and includes looking at actions not related to software or an interaction device Start with a user goal which is examined and the main tasks for achieving it are identified Tasks are sub-divided into sub-tasks From: www.id-book.com

52. Example Hierarchical Task Analysis 0.In order to borrow a book from the library 1.go to the library 2.find the required book 2.1 access library catalogue 2.2 access the search screen 2.3 enter search criteria 2.4 identify required book 2.5 note location 3.go to correct shelf and retrieve book 4.take book to checkout counter From: www.id-book.com

53. Example Hierarchical Task Analysis (plans) plan 0: do 1-3-4. If book isn’t on the shelf expected, do 2-3-4. plan 2: do 2.1-2.4-2.5. If book not identified do 2.2-2.3-2.4. From: www.id-book.com

54. Example Hierarchical Task Analysis (graphical) Borrow a book from the library go to the library find required book retrieve book from shelf take book to counter 3214 0 access catalog access search screen enter search criteria identify required book note location plan 0: do 1-3-4. If book isn’t on the shelf expected, do 2-3-4. plan 2: do 2.1-2.4-2.5. If book not identified from information available, do 2.2-2.3-2.4-2.5 2.12.22.32.42.5 From: www.id-book.com

55. Summary Getting requirements right is crucial There are different kinds of requirement, each is significant for interaction design The most commonly-used techniques for data gathering are: questionnaires, interviews, focus groups, direct observation, studying documentation and researching similar products Scenarios, use cases and essential use cases can be used to articulate existing and envisioned work practices. Task analysis techniques such as HTA help to investigate existing systems and practices From: www.id-book.com