1. 1 The Design Process Lecture 9 Date: 2 nd March

2. 2 Overview Life-Cycle Models in HCI 4 basic activities in HCI Requirements Design Develop/Build Evaluation

3. 3 Lifecycle Models Show how activities are related to each other Lifecycle models are: —management tools —simplified versions of reality Many lifecycle models exist, for example: —from software engineering: waterfall, spiral, JAD/RAD —from HCI: Star, usability engineering Life-Cycle Models

4. 4 A simple interaction design model Evaluate (Re)Design Identify needs/ establish requirements Build an interactive version Final product Exemplifies a user-centered design approach Life-Cycle Models

5. 5 Traditional ‘waterfall’ lifecycle Requirements analysis Design Code Test Maintenance Life-Cycle Models

6. 6 A Lifecycle for RAD (Rapid Applications Development) JAD workshops Project set-up Iterative design and build Engineer and test final prototype Implementation review Life-Cycle Models

7. 7 Spiral Model (Barry Boehm) Important features: —Risk analysis —Prototyping —Iterative framework allowing ideas to be checked and evaluated —Explicitly encourages alternatives to be considered Good for large and complex projects but not simple ones Life-Cycle Models

8. 8 Spiral Lifecycle Model From cctr.umkc.edu/~kennethjuwng/spiral.htm Life-Cycle Models

9. 9 The Star Lifecycle Model Suggested by Hartson and Hix (1989) Important features: —Evaluation at the center of activities —No particular ordering of activities. Development may start in any one —Derived from empirical studies of interface designers Life-Cycle Models

10. 10 The Star Model (Hartson and Hix, 1989) Evaluation Conceptual/ formal design Requirements specification Prototyping task/functional analysis Implementation Life-Cycle Models

11. 11 Usability engineering Lifecycle Model Reported by Deborah Mayhew Important features: Holistic view of usability engineering Provides links to software engineering approaches, e.g. OOSE Stages of identifying requirements, designing, evaluating, prototyping Can be scaled down for small projects Uses a style guide to capture a set of usability goals Life-Cycle Models

12. 12 Usability engineering Lifecycle Model Life-Cycle Models

13. 13 Design Model Requirements Design Build/Develop Evaluate

14. 14 Requirements A requirement is something the product must do or a quality that the product must have Requirements

15. 15 Requirements Different kinds of requirements: Functional:Functional: What the system should do Historically the main focus of requirements activities Non-functional:Non-functional: memory size, response time.. Data: Data: What kinds of data need to be stored? How will they be stored (e.g. database)? Usability:Usability: learnability throughput flexibility attitude Requirements

16. 16 Requirements Determining Usability Requirements: Task AnalysisTask Analysis User AnalysisUser Analysis Environment AnalysisEnvironment Analysis Requirements

17. 17 Requirements Task Analysis Task analysis describes the behavior of a system Determine cognitive and other characteristics required of users by system search strategy prereq knowledge cognitive loading etc. Observe existing work practices Create scenarios of actual use new ideas before building software! Get rid of problems early in the design process Requirements

18. 18 Requirements Task Analysis Who is going to use the system? What tasks do they now perform? What tasks are desired? How are the tasks learned? Where are the tasks performed? What’s the relationship between user & data? Requirements

19. 19 Requirements Types of Task Analysis Task Decomposition Knowledge Based Analysis Entity-Relationship Based Analysis Requirements

20. 20 Requirements Task Decomposition Task Decomposition: top-down process in which a task is split into component sub-tasks: Select a task Based your data (from observation, documentation, and expert advice), divide the task into sub-tasks. If your stopping rule has not been reached, repeat steps 1-3 for each of the new sub-tasks. The stopping condition you use - the level of detail you recurse to - depends on your purpose in performing the analysis. Requirements

21. 21 Requirements Knowledge-Based Analysis Knowledge-based analysis works from the bottom up The starting point for the process is a list of all of the objects and actions that are relevant to the task that is being analyzed, based on data collected. The objects are then arranged into groups based on similarity or shared traits. The groups themselves are then grouped together, building progressively more abstract categories Requirements

22. 22 Requirements Entity-Relationship Based Analysis Entity-relationship analysis is also a bottom-up approach to task analysis, inheriting much of its structure from object-oriented programming. Entity-relationship analysis concerns itself with objects, actions, and their relationship: Objects - simple objects, actors, composite objects, and events. Object-relationship analysis - relationship between objects Requirements

23. 23 Requirements User Analysis User Analysis Who are they?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 Requirements

24. 24 Requirements Environment Analysis 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 Requirements

25. 25 Design Model Requirements Design User-centred design Build/Develop Evaluate

26. 26 User-Centred Design Why involve users at all? What is a user-centered approach? Understanding user’s work Ethnographic observation Participatory design PICTIVE CARD User-Centred Design

27. 27 Why involve Users? Expectation management Realistic expectations No surprises, no disappointments Timely training Communication, but no hype Ownership Make the users active stakeholders More likely to forgive or accept problems Can make a big difference to acceptance and success of product User-Centred Design

28. 28 What is a User-Centred Approach? User-centered approach is based on: Early focus on users and tasks: directly studying cognitive, behavioural, anthropomorphic & attitudinal characteristics Empirical measurement: users’ reactions and performance to scenarios, manuals, simulations & prototypes are observed, recorded and analysed Iterative design: when problems are found in user testing, fix them and carry out more tests User-Centred Design

29. 29 Ethnographic Observation Preparation Understand organization policies and work culture. Familiarize yourself with the system and its history. Set initial goals and prepare questions. Gain access and permission to observe/interview. Field Study Establish rapport with managers and users. Observe/interview users in their workplace and collect subjective/objective quantitative/qualitative data. Follow any leads that emerge from the visits. User-Centred Design

30. 30 Ethnographic Observation Analysis Compile the collected data in numerical, textual, and multimedia databases. Quantify data and compile statistics. Reduce and interpret the data. Refine the goals and the process used. Reporting Consider multiple audiences and goals. Prepare a report and present the findings. User-Centred Design

31. 31 Participatory Design User-Centred Design

32. 32 Participatory Design User-Centred Design Controversial More user involvement brings: more accurate information about tasks more opportunity for users to influence design decisions a sense of participation that builds users' ego investment in successful implementation potential for increased user acceptance of final system

33. 33 Participatory Design User-Centred Design However, extensive user involvement may: be more costly lengthen the implementation period build antagonism with people not involved or whose suggestions rejected force designers to compromise their design to satisfy incompetent participants build opposition to implementation exacerbate personality conflicts between design-team members and users show that organizational politics and preferences of certain individuals are more important than technical issues

34. 34 Participatory DesignPICTIVE Plastic Interface for Collaborative Technology Initiatives through Video Exploration Intended to empower users to act a full participants in design Materials used are: Low-fidelity office items such as pens, paper, sticky notes Collection of (plastic) design objects for screen and window layouts Equipment required: Shared design surface, e.g. table Video recording equipment User-Centred Design

35. 35 Participatory Design PICTIVE (cont.) Before a PICTIVE session: Users generate scenarios of use Developers produce design elements for the design session A PICTIVE session has four parts: Stakeholders all introduce themselves Brief tutorials about areas represented in the session (optional) Brainstorming of ideas for the design Walkthrough of the design and summary of decisions made User-Centred Design

36. 36 Participatory DesignCARD Collaborative Analysis of Requirements & Design Similar to PICTIVE but at a higher level of abstraction: explores work flow not detailed screen design Uses playing cards with pictures of computers and screen dumps Similar structure to the session as for PICTIVE PICTIVE and CARD can be used together to give complementary views of a design User-Centred Design

37. 37 Summary of Lecture Lifecycle models Software engineering lifecycle models HCI lifecycle models Usability Engineering Lifecycle Model Star Lifecycle Model HCI design models Requirements Design User-centred design Develop/Build Evaluation

38. 38 Terms of Reference Preece, J. et al. (2002) Interaction Design Shneiderman, B. & Plaisant, C. (2005) Designing the User Interface Benyon, D. et al (2005) Designing Interactive Systems Helander, M. et al (1997) Handbook of Human- Computer Interaction Hartson, R. & Hix, D. (1989) Towards Empirically Derived Methodologies and Tools for HCI Development Mayhew, D. (1995) The Usability Engineering Lifecycle Alan Dix et al (1993) Human Computer Interaction References