1. Identifying needs and establishing requirements

2. Overview The importance of requirements Different types of requirements Data gathering Task descriptions:Scenarios Use Cases Essential use cases Task analysis: HTA

3. What, how and why? What Two aims: 1. Understand as much as possible about users, task, context 2. Produce a stable set of requirements How: Data gathering activities Data analysis activities Expression as ‘requirements’ All of this is iterative

4. What, how and why? Why: Requirements definition: the stage where failure occurs most commonly Getting requirements right is crucial

5. Different kinds of requirements Functional: —What the system should do —Historically the main focus of requirements activities (Non-functional: memory size, response time... ) Data: —What kinds of data need to be stored? —How will they be stored (e.g. database)?

6. Different kinds of requirements Environment or context of use: —physical: dusty? noisy? vibration? light? heat? humidity? …. (e.g. OMS insects, ATM) —social: sharing of files, of displays, in paper, across great distances, work individually, privacy for clients —organisational: hierarchy, IT department’s attitude and remit, user support, communications structure and infrastructure, availability of training

7. Different kinds of requirements Users: Who are they? —Characteristics: ability, background, attitude to computers —System use: novice, expert, casual, frequent —Novice: step-by-step (prompted), constrained, clear information —Expert: flexibility, access/power —Frequent: short cuts —Casual/infrequent: clear instructions, e.g. menu paths

8. Different kinds of requirements Usability: learnability, throughput, flexibility, attitude Note that user requirements and usability requirements refer to different things

9. Data gathering techniques (1) Questionnaires: —A series of questions designed to elicit specific information —Questions may require different kinds of answers: simple YES/NO; choice of pre-supplied answers; comment —Often used in conjunction with other techniques —Can give quantitative or qualitative data —Good for answering specific questions from a large, dispersed group of people

10. Data gathering techniques (2) Interviews: —Forum for talking to people —Structured, unstructured or semi-structured —Props, e.g. sample scenarios of use, prototypes, can be used in interviews —Good for exploring issues —But are time consuming and may be infeasible to visit everyone

11. Data gathering techniques (3) Workshops or focus groups: —Group interviews —Good at gaining a consensus view and/or highlighting areas of conflict

12. Data gathering techniques (4) Naturalistic observation: —Spend time with stakeholders in their day-to-day tasks, observing work as it happens —Gain insights into stakeholders’ tasks —Good for understanding the nature and context of the tasks —But, it requires time and commitment from a member of the design team, and it can result in a huge amount of data —Ethnography is one form

13. Data gathering techniques (5) Studying documentation: —Procedures and rules are often written down in manuals —Good source of data about the steps involved in an activity, and any regulations governing a task —Not to be used in isolation —Good for understanding legislation, and getting background information —No stakeholder time, which is a limiting factor on the other techniques

14. Some basic guidelines Focus on identifying the stakeholders’ needs Involve all the stakeholder groups Involve more than one representative from each stakeholder group Use a combination of data gathering techniques

15. Some basic guidelines Support the process with props such as prototypes and task descriptions Run a pilot session You will need to compromise on the data you collect and the analysis to be done, but before you can make sensible compromises, you need to know what you’d really like Consider carefully how to record the data

16. 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

17. Task descriptions Scenarios an informal narrative story, simple, ‘natural’, personal, not generalisable Use cases —assume interaction with a system —assume detailed understanding of the interaction Essential use cases —abstract away from the details —does not have the same assumptions as use cases

18. Scenario for shared calendar “The user types in all the names of the meeting participants together with some constraints such as the length of the meeting, roughly when the meeting needs to take place, and possibly where it needs to take place. The system then checks against the individuals’ calendars and the central departmental calendar and presents the user with a series of dates on which everyone is free all at the same time. Then the meeting could be confirmed and written into people’s calendars. Some people, though, will want to be asked before the calendar entry is made. Perhaps the system could email them automatically and ask that it be confirmed before it is written in.”

19. Use case for shared calendar 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 emails all the meeting participants informing them of them appointment

20. Alternative courses for shared calendar Some alternative courses: 5.If the list of people is invalid, 5.1The system displays an error message. 5.2The system returns to step 2. 8.If no potential dates are found, 8.1The system displays a suitable message. 8.2The system returns to step 5.

21. Example use case diagram for shared calendar

22. Example essential use case for shared calendar arrangeMeeting USER INTENTION SYSTEM RESPONSIBILITY arrange a meeting request meeting attendees & constraints identify meeting attendees & constraints search calendars for suitable dates suggest potential dates choose preferred date book meeting

23. Task analysis Task descriptions are often used to envision new systems or devices Task analysis is used mainly to investigate an existing situation It is important not to focus on superficial activities What are people trying to achieve? Why are they trying to achieve it? How are they going about it? Many techniques, the most popular is Hierarchical Task Analysis (HTA)

24. 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

25. 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

26. 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 and workshops, naturalistic observation, studying documentation 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

27. Design, prototyping and construction

28. Overview Prototyping and construction Conceptual design Physical design Tool support

29. What is a prototype? In interaction design it can be (among other things): a series of screen sketches a storyboard, i.e. a cartoon-like series of scenes a Powerpoint slide show a video simulating the use of a system a lump of wood (e.g. PalmPilot) a cardboard mock-up a piece of software with limited functionality written in the target language or in another language

30. Why prototype? Evaluation and feedback are central to interaction design Stakeholders can see, hold, interact with a prototype more easily than a document or a drawing Team members can communicate effectively You can test out ideas for yourself It encourages reflection: very important aspect of design Prototypes answer questions, and support designers in choosing between alternatives

31. What to prototype? Technical issues Work flow, task design Screen layouts and information display Difficult, controversial, critical areas

32. Low-fidelity Prototyping Uses a medium which is unlike the final medium, e.g. paper, cardboard Is quick, cheap and easily changed Examples: sketches of screens, task sequences, etc ‘Post-it’ notes storyboards ‘Wizard-of-Oz’

33. Storyboards Often used with scenarios, bringing more detail, and a chance to role play It is a series of sketches showing how a user might progress through a task using the device Used early in design

34. Sketching Sketching is important to low-fidelity prototyping Don’t be inhibited about drawing ability. Practice simple symbols

35. Index cards (3 X 5 inches) Each card represents one screen Often used in website development Using index cards

36. ‘Wizard-of-Oz’ prototyping The user thinks they are interacting with a computer, but a developer is responding to output rather than the system. Usually done early in design to understand users’ expectations What is ‘wrong’ with this approach? >Blurb blurb >Do this >Why? User

37. High-fidelity prototyping Uses materials that you would expect to be in the final product. Prototype looks more like the final system than a low-fidelity version. For a high-fidelity software prototype common environments include Macromedia Director, Visual Basic, and Smalltalk. Danger that users think they have a full system…….see compromises

38. Compromises in prototyping All prototypes involve compromises For software-based prototyping maybe there is a slow response? sketchy icons? limited functionality? Two common types of compromise ‘horizontal’: provide a wide range of functions, but with little detail ‘vertical’: provide a lot of detail for only a few functions Compromises in prototypes mustn’t be ignored. Product needs engineering

39. Construction Taking the prototypes (or learning from them) and creating a whole Quality must be attended to: usability (of course), reliability, robustness, maintainability, integrity, portability, efficiency, etc Product must be engineered Evolutionary prototyping ‘Throw-away’ prototyping

40. Conceptual design: from requirements to design Transform user requirements/needs into a conceptual model “a description of the proposed system in terms of a set of integrated ideas and concepts about what it should do, behave and look like, that will be understandable by the users in the manner intended” Don’t move to a solution too quickly. Iterate, iterate, iterate Consider alternatives: prototyping helps

41. Three perspectives for a conceptual model Which interaction mode? How the user invokes actions Activity-based: instructing, conversing, manipulating and navigating, exploring and browsing. Object-based: structured around real-world objects

42. Three perspectives for a conceptual model Which interaction paradigm? desktop paradigm, with WIMP interface (windows, icons, menus and pointers), ubiquitous computing pervasive computing wearable computing mobile devices and so on. Is there a suitable metaphor? (contd)….

43. Is there a suitable metaphor? Interface metaphors combine familiar knowledge with new knowledge in a way that will help the user understand the product. Three steps: understand functionality, identify potential problem areas, generate metaphors Evaluate metaphors: How much structure does it provide? How much is relevant to the problem? Is it easy to represent? Will the audience understand it? How extensible is it?

44. Expanding the conceptual model What functions will the product perform? What will the product do and what will the human do (task allocation)? How are the functions related to each other? sequential or parallel? categorisations, e.g. all actions related to telephone memory storage What information needs to be available? What data is required to perform the task? How is this data to be transformed by the system?

45. Using scenarios in conceptual design Express proposed or imagined situations Used throughout design in various ways scripts for user evaluation of prototypes concrete examples of tasks as a means of co-operation across professional boundaries Plus and minus scenarios to explore extreme cases

46. Using prototypes in conceptual design Allow evaluation of emerging ideas Low-fidelity prototypes used early on, high- fidelity prototypes used later

47. Physical design: getting concrete Considers more concrete, detailed issues of designing the interface Iteration between physical and conceptual design Guidelines for physical design Nielsen’s heuristics Shneiderman’s eight golden rules Styles guides: commercial, corporate decide ‘look and feel’ for you widgets prescribed, e.g. icons, toolbar

48. Physical design: getting concrete Different kinds of widget (dialog boxes, toolbars, icons, menus etc) menu design icon design screen design information display

49. Menu design How long is the menu to be? In what order will the items appear? How is the menu to be structured, e.g. when to use sub-menus, dialog boxes? What categories will be used to group menu items?

50. Menu design How will division into groups be denoted, e.g. different colors, dividing lines? How many menus will there be? What terminology to use? (results of requirements activities will indicate this) How will any physical constraints be accommodated, e.g. mobile phone?

51. Icon design Good icon design is difficult Meaning of icons is cultural and context sensitive Some tips: always draw on existing traditions or standards concrete objects or things are easier to represent than actions From clip art, what do these mean to you?

52. Screen design Two aspects: How to split across screens moving around within and between screens how much interaction per screen? serial or workbench style? Individual screen design white space: balance between enough information/interaction and clarity grouping items together: separation with boxes? lines? colors?

53. Screen design: splitting functions across screens Task analysis as a starting point Each screen contains a single simple step? Frustration if too many simple screens Keep information available: multiple screens open at once

54. Screen design: individual screen design Draw user attention to salient point, e.g. colour, motion, boxing Animation is very powerful but can be distracting Good organization helps: grouping, physical proximity Trade off between sparse population and overcrowding

55. Information display Relevant information available at all times Different types of information imply different kinds of display Consistency between paper display and screen data entry

56. Summary Different kinds of prototyping are used for different purposes and at different stages Prototypes answer questions, so prototype appropriately Construction: the final product must be engineered appropriately Conceptual design (the first step of design) Physical design: e.g. menus, icons, screen design, information display Prototypes and scenarios are used throughout design