1 The Design Process Lecture 6 DeSiaMorewww.desiamore.com/ifm

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

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 DeSiaMorewww.desiamore.com/ifm

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 DeSiaMorewww.desiamore.com/ifm

5 Traditional ‘waterfall’ lifecycle Requirements analysis Design Code Test Maintenance Life-Cycle Models DeSiaMorewww.desiamore.com/ifm

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 DeSiaMorewww.desiamore.com/ifm

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 DeSiaMorewww.desiamore.com/ifm

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

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

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

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 DeSiaMorewww.desiamore.com/ifm

12 Usability engineering Lifecycle Model Life-Cycle Models DeSiaMorewww.desiamore.com/ifm

13 Design Model Requirements Design Build/Develop Evaluate DeSiaMorewww.desiamore.com/ifm

14 Requirements A requirement is something the product must do or a quality that the product must have Requirements DeSiaMorewww.desiamore.com/ifm

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 DeSiaMorewww.desiamore.com/ifm

16 Requirements Determining Usability Requirements: Task AnalysisTask Analysis User AnalysisUser Analysis Environment AnalysisEnvironment Analysis Requirements DeSiaMorewww.desiamore.com/ifm

17 Requirements Task Analysis 1. Task Analysis Task analysis describes the behavior of a system Determine cognitive and other characteristics required of users by system Observe existing work practices Create scenarios of actual use new ideas before building software! Get rid of problems early in the design process Requirements DeSiaMorewww.desiamore.com/ifm

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 DeSiaMorewww.desiamore.com/ifm

19 Requirements Types of Task Analysis Task Decomposition (top-down) 1.Select a task 2.Divide the task into sub-tasks 3.If your stopping rule has not been reached, repeat steps 1-3 for each of the new sub-tasks. Knowledge Based Analysis (bottom-up) 1.List all of the objects and actions that are relevant to the task 2.Groups based on similarity or shared traits 3.The groups themselves are then grouped together, building progressively more abstract categories Entity-Relationship Based Analysis (bottom-up) concerns itself with objects, actions, and their relationship Requirements DeSiaMorewww.desiamore.com/ifm

20 Requirements 2. User Analysis 2. 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 DeSiaMorewww.desiamore.com/ifm

21 Requirements Environment Analysis 3. 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 DeSiaMorewww.desiamore.com/ifm

22 Design Model Requirements Design User-centred design Build/Develop Evaluate DeSiaMorewww.desiamore.com/ifm

23 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 DeSiaMorewww.desiamore.com/ifm

24 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 DeSiaMorewww.desiamore.com/ifm

25 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 DeSiaMorewww.desiamore.com/ifm

26 Ethnographic Observation Preparation Understand organisation policies and work culture. Familiarise 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 DeSiaMorewww.desiamore.com/ifm

27 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 DeSiaMorewww.desiamore.com/ifm

28 Participatory Design User-Centred Design DeSiaMorewww.desiamore.com/ifm

29 Participatory Design User-Centred Design Participatory design is an approach to design that attempts to actively involve the end users in the design process. It assumes that users should play an active role in the creative process: users envision the future by identifying the defining moments from their perspective DeSiaMorewww.desiamore.com/ifm29

30 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 DeSiaMorewww.desiamore.com/ifm

31 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 organisational politics and preferences of certain individuals are more important than technical issues DeSiaMorewww.desiamore.com/ifm

32 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 DeSiaMorewww.desiamore.com/ifm

33 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 DeSiaMorewww.desiamore.com/ifm

34 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 DeSiaMorewww.desiamore.com/ifm

35 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 DeSiaMorewww.desiamore.com/ifm

36 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 DeSiaMorewww.desiamore.com/ifm