1. Design Concepts • Find the representation best suited to communicating the behavior of the software in question. • “To get a good idea, get lots of ideas” (Rettig, 1994) – Fudd’s 1st Law of Creativity • Provide a good conceptual model • Make things visible • Don Norman gave us design principles.

2. Design Principles - Norman • Some important interface design principles from “The Design of Everyday Things”are: • Visibility • Affordance • Naturalmapping • Constraints • Conceptualmodels • Feedback

3. Visibility • Good user interfaces are Visible. • The user is able to perform tasks by making selections and by manipulating objects. • A features existence is obvious by simple inspection. • To be really visible a feature must be understood by the user. • Visible user interfaces often result from a noun-then-verb interaction .

4. Visible Interfaces • Some common visible interfaces: • Commands • Menu bars • Toolbars with tool tips • Coordinated menu bars and toolbars • Hyperlinks • Windows • Dialog boxes • Wizards

5. Visible Interfaces • Controls • Command buttons • Edit or text boxes • Edit boxes with spin boxes and browse buttons • Combo / list boxes … etc

6. Visible Interfaces • Visual Information • Plain Text • Previews • Tooltips – quick way to pass on info’. • Cursor hinting

7. Affordances • Are the perceived and actual fundamental properties of the object that determine how it could possibly be used. • Appearance indicates how an object should be used. • Actual affordances play a relatively minor role in screen-based products.

8. Constraints • Constraints reduce the number of ways to perform a task • Object should contain knowledge. • Visible Constraints • Set limitations on the actions possible, perceived from the appearance of the object • Provides users with a range of usage possibilities

9. Conceptual Model By conceptual model we mean a description of the proposed system in terms of a set of integrated ideas and concepts about what it should do, behave and look like, that will be understandable by the users in the manner intended.

10. Understandable Actions • Causality • False causality • Incorrect effect • Invisible effect • Transfer effects

11. Population Stereotypes • Populations learn idioms that work in a certain way: • Idioms vary in different cultures • Ignoring or changing stereotypes • Very difficult to change stereotypes

12. Functionality • A features functionality is indicated by the following: • Visual attributes • Simple experimentation • Help • Standards or convention • Common sense or real-life experience • Part of culture

13. Who Do You Design For? • People are different • Rarely possible to accommodate all people • Rules of thumb for design

14. Who do you Design For?

15. Who do you Design For?

16. Why Design is Hard • The number of things to control has increased dramatically • Display has become increasingly artificial • Feedback has become more complex, subtle and less natural. • Marketplace pressures • Cost and appearance usually override human factors design