User Interface Design Basics: Achieving Goals within Constraints

1. Lecture 8 Unit 4: Designing User Interfaces

2. Interaction Design Basics • Interaction design is about creating interventions in often complex situations using technology of many kinds including PC software, the web and physical devices.

3. Design involves • Achieving goals within constraints and trade-off between goals & constraints • Understanding the raw materials: computer and human • Accepting limitations of humans and of design.

4. The design process has several stages and is iterative and never complete.

5. Where does interaction start? • It starts with getting to know the users and their context: • Finding out who they are and what they are like… probably not like you! • Talking to them, watching them.

6. What are scenarios? • These are rich design stories, which can be used and reused throughout design: • They help us see what users will want to do • They give a step-by-step walkthrough of users’ interactions: including what they see, do and are thinking.

7. Navigation by the user • Users need to find their way around a system. This involves: • Helping users know where they are, where they have been and what they can do next • Creating overall structures that are easy to understand and fit the users’ needs • Designing comprehensible screens and control panels.

8. Complexity of design • Complexity of design means we don’t get it right first time: • So we need iteration and prototypes to try out and evaluate • But iteration can get trapped in local maxima, designs that have no simple improvements, but are not good • Theory and models can help give good start points.

9. What is design? • It is simply achieving goals within constraints.

10. Golden rule of design: • Understand computers • Limitations, capacities, tools, platforms • Understand people • Psychological, social aspects, human error.

11. Human considerations: • To err is human • The central message – the user

12. The process of design: • What is wanted • Analysis • Design (iteration and prototyping) • Implement and deploy

13. User Focus • Know your users • Who are they? • Probably not like you! • Talk to them. • Watch them.

14. Screen Design and Layout: • Tools for layout: • Grouping and structure • Order of groups and items • Decoration • Alignment • White space • User action and control: • Entering information • Knowing what to do • Affordances

15. Screen Design and Layout: • Appropriate appearance: • Presenting information • Aesthetics and utility • Making a mess of it: colour and 3D • Localization / internationalization

16. HCI in the software process • Software Engineering provides a means of understanding the structure of the design process, and that process can be assessed for its effectiveness in interactive system design.

17. HCI in the software process • Usability engineering promotes the use of explicit criteria to judge the success of a product in terms of its usability. • Iterative design practices work to incorporate crucial customer feedback early in the design process to inform critical decisions which affect usability.

18. HCI in the software process • Design involves making many decisions among numerous alternatives. Design rationale provides an explicit means of recording those design decisions and the context in which the decisions were made.