DDPC 1633/DDC 3153 Human-Computer Interaction/ User Interface Programming

1. DDPC 1633/DDC 3153Human-Computer Interaction/ User Interface Programming Chapter 2 Making interactive systems feel natural for users

2. At the end of this lecture you should be able to … 1. Define what natural computing is and explain the main principles of natural computing 2. Explain the key concepts of user-centred system design (UCSD) 3. Explain what interactive design is

3. 1. Natural computing The study of • how people process and store information, • manipulate symbols, • ascribe personal values to events, • attribute cultural and emotive judgements and • use interactive artefacts to enhance our lifestyles

4. Natural computing • Natural computing is not the same as saying the human brain is a computer. The human brain is MUCH more. • Information processing is just one of the capabilities of the human brain. The main idea of natural computing is that information processing is a natural process for us. • The user perspective • Provide conceptual framework for user modelling • The designer's perspective • Will provide better understanding of designs that will support users • The sustainability perspective • Need for well-designed systems is a necessity, not a luxury

5. 2. Key features of user-centred system design • A central focus on the people who will use the systems, on their preferences and requirements • Building simple models of the users, the tasks and the technological systems • An iterative process • Prototyping and the evaluation of alternatives by users. • Designers have vast number of key decisions to make • Designers work with their own ‘mental model’ – can become subjective

6. UCSD

7. The user or users • What do you think of when you read the phrase 'the user'? Do you think of: • Someone like yourself? • A stereotype 'user'? • A group of 'typical users'? • You picture individuals, each with different skills and preferences, different priorities and objectives? • Rather use ‘users’ – not one typical user

8. Is UCSD sufficient? UCSD may not be enough – it may be impossible to capture needs/preferences of all users in 1 design People may need the additional facility to: • Customise a system • Add assistive technology for extreme circumstances or disability • Have adaptable systems that respond to the ways in which they are used or to a user's known profile (personalisation)

9. Six elements of natural computing • Natural computing • A research and application area that draws from cognitive science, cognitive psychology, HCI, interaction design, sociology and anthropology • What can users do? • People drive technology to achieve objectives, not the other way round • Modelling users • Understanding the domain – wide diversity of disciplines • Understanding human learning • Meaning as a basis for practical action – links between theory & practice

10. Core concepts These are common to both natural computing and user-centred system design • User model • Universal access • Design for all • Inclusive design • Task models • Technological platform

11. 1. User model • Vary from: • Simple list of preferences to • Psychological profile • Strengths and weaknesses, skills, interests, potential, disabilities, age, culture, experience. • The more complete the model • the better it can be used in system design, but • the more expensive it is in terms of time, expertise and money to develop it. • Don’t think of the typical user only – also include the diversity and complexity of user population

12. 2. Universal access Universal access is the objective of making systems that are accessible: • anytime, • anywhere and • to anyone of the intended user population.

13. 3. Design for all It is similar to 'universal access', but also promotes the notion of: • careful design and design standards, so that users with special needs are not excluded from the use of a system.

14. 4. Inclusive design • Universal access and design for all are essentially qualitative • Inclusive design is a quantitative measure by which designers can calculate the numbers of users who are excluded by specific design features (based on abilities of users) • Understanding and quantifying the consequences of different design options for diverse range of potential users

15. 5. Task models • Output of task analysis • You must identify the key features of the task to be achieved – and recognise those aspects that must or can be changed.

16. 6. Technological platform In the earlier days of system design • technology placed severe restrictions on the functionality of proposed systems These days • technological options are less restrictive and, we can expect our expectations to be fulfilled by the technology

17. Interactive design • UCSD is an interactive and iterative process • Designer and design process work interactively • Emphasis on research, design and evaluation in cycle • Initial good ideas are iteratively revised in the light of experience and evaluation • Main stages of UCSD (refer to figure 2.1) • Task analysis • Requirements specification • Prototyping • Evaluation • Creation and reconciliation of three elements • User model • Task model • Technology model

18. Strengths and weaknesses of interactive systems • Modern interactive systems can be powerful because they draw on powerful technology • If power is not utilised = weakness • Interactive systems may provide useful functions • Lack of usefulness = weakness • Interactive systems differ in the extent that they are usable • Lack of usability = weakness • Accessibility varies between good and poorly designed systems • Poor accessibility = weakness

19. Summary… Natural computing provides a basis to begin to understand people and systems, and how people might use technology to good effect

20. Exercise • What is UCSD? • What is natural computing? • What are six elements of natural computing? • What are the properties of an interactive system that make it easy to use?