Concepts of user-centered design

Transcription

1 Lecture 1 Concepts of user-centered design

2 What is UCD? Primary goad: making products usable

3 Is there any difference? Usable Usefulness Usability

4 Why important? Increased productivity Reduced errors Reduced training and support costs Improved acceptance Enhanced reputation

5 How to do? Involving users in the design and testing process of the system Modify prototypies based on user s feedback Iteration Multi-disciplinary design teams

6 Transformation Traditional Approach Produce UCD Approach Technology driven Component focus Limited multidiscipline cooperation Focus on internals architecture No specialization in user experience Some competitive focus Development prior to user validation Product defect view of quality Limited focus on user measurement Focus on current customers vs. User driven Solutions focus Multidisciplinary team work Focus on externals design Specialization in user experience Focus on competition Develop only user validated designs User view of quality Prime focus on user measurement Focus on current and future customers

7 Definition of UCD User engagement in the design process Users having real decision-making powers Users having appropriate mechanism for communication with, and negotiation with, developers A socio-technical design process Containing iterative and evolutionary approach Where consideration is given to job satisfaction

8 6. Context of evaluation Usability evaluation Meets all the requirements 1. Plan the human centrd process Design philosophy Identify design team and users Time-line Success criteria 2. Specify the context of use Understand the characteristics of User, tasks, organization, Environment Task analysis 5. Evaluate designs against user requirements Getting feedback for design Assess the achievement of user and Organizational objectives 3. Specify the user and organizational requirements Allocation of tasks among users Functional requirements Performance criteria Usability criteria ISO UCD process 4. Produce design solutions Collect knowledges for design Concrete design solution Prototypes and user tests Iterating above process untill satisfy

9 Planning Usablity planning and scoping Usability cost-benefit analysis

10 Methods to support human- centred design Context of use within usability activities by Martin Maguire 2001

11 Context of use Identify stakeholders Context of use analysis Survey of existing users Field study/user observation Field study/user observation Diary keeping Task analysis

12 the importance of selecting representative users realistic tasks

13 Laboratory tests vs field observation Labs: the aim is to test whether a product meets certain predefined usability criteria Field studies: to identify special problems associated with the integration of the product into the actual working environment the acceptability of a product

14 there are possible problems in comparing the results of the different tests; however the benefits of having both types of test data outweigh the negative factors

15 Important with context The usability of a product depends on its Context of Use. Products should be designed for specific contexts. Measurement of usability must always be carried out in an appropriate context. Usability measurements should always be accompanied by a detailed description of the context of measurement.

16 What is context? The user/stakeholder Task and equipment Physical and social environments

17

18 Requirements Stakeholder analysis User cost-benefit analysis User requirements interview Focus groups Personas Existing system/competitor analysis Task/function mapping Allocation of function User, usability and organizational requirements

19 Design Brainstorming Parallel design Design guidelines and standards Storyboarding Affinity diagram Card sorting Paper prototyping Wizard-of-Oz prototyping Organizational prtotyping

20 Evaluation Participatory evaluation Assisted evaluation Heuristic or expert evaluation Controlled user testing Satisfaction questionnaires Assessing cognitive workload Critical incidents Post-experience interviews

21 History Norman and Draper, 1986 (originating) ISO TC159/SC4: ergonomics of human-system interaction (1986) ISO Ergonomic requirements for office work with visual display terminals guidance on usability (1999) ISO (1999):Human-centred design processes for interactive systems ISO TR (2000): Human-centred lifecycle process descriptions

22 A survey of user-centered design practice Karel Vredenburg, et al 2002 Program Director for Design Leadership at IBM and have responsibility for visual and interaction design strategy and tools.

23 Earlier studies The major obstacles for using UCD process: Resource constraints Lack of knowledge Widely used methods: Informal and less structured methods Top three best selling activities: Customer interviews Paper or other prototyping Usability test

24 Questionnaire study Over 100 peoples from 96 companies participated into study UCD methods made significant impact on UCD methods made significant impact on product development

25

26

27 Jan Gulliksen 2003 Key principles for user-centred systems design Main argument: There has been the lack of an agreement upon definition of UCSD You must involve users in system design while leaving fairly open how this is accomplished

28 Results Based on industrial practices in Sweden Develop the useful principles

29 Obstacle factors Resource constraints (28.6%), Resistance to UCD/usability (26%) lack of understanding of the usability concept (17.3%) Lack of communication betweendesign and results (13.3%) lack of trained usability experts (6.1%). Rosenbaum, et al, 2000

30 Situation in Sweden No longer a lack of HCI knowledge within the industry a lack of respect and support for usability issues A lack of involving management and other stakeholders in the process.

31 UCD principles (Gulliksen 2003) User focus Active user involvement Evolutionary system development Simple design representations Prototype Evaluation use in context Explicit and conscious design activities A professional attitude Usability champion Holistic design Processes customization A user-centered attitude should always be established

32 What is up? Read through the article by Martin Magnuire (2001 b) Methods to support human-centred design Discuss among group members: Which methods you have used/familiar, which is not? Bring a question to the classroom for further lecturing/discussion Bring up 1 questions each group. The answers to your questions cannot be found from the articles Present your question to the class.