why good interface design?

1. why good interface design? • affordances • mapping functions • mental models • forcing functions • feedback • automatic learning • reduces input and usage errors • lowers the cost of system support • makes users more productive • users care about... • their interaction with the system • usefulness of the system today and in the future • a good user interface... • allows people to learn by using the system • allows the design to suggest the correct process model • builds on the user’s prior learning • help users do their work efficiently and effectively

2. evaluate implement interface (input and output) design is an iterative process design • inputs to interface design: • understanding of the users • best-practice considerations • evaluation with the users • evaluation without the users • user involvement: • task analysis • storyboards • dialogue charts • prototyping • etc. source: Andy Cockburn University of Canterbury NZ

3. design problems • avoid design inertia - don’t let early • bad design decisions stay bad • correctly distinguish between problems • and symptoms in the user domain • it’s hard for users to communicate problems • designers are uniquely unqualified to evaluate • their own designs • it’s not easy to distinguish between the • designer’s model and the user’s model source: Andy Cockburn University of Canterbury NZ

4. design opportunities • to get a good idea, get lots of ideas • delay commitment • try one or more of the following validation techniques • storyboards • dialogue charts • prototypes • role-play • formal empirical evaluation • focus/test groups

5. input from user /output from system

6. input from user /output from system

8. input design objectives • select best media and methods • develop efficient input procedures • reduce input volume • reduce input errors designing input • users and system designers care about: • data entry at source, without delays • data entered only once • data verified where/when input • automated data entry where possible • controlled access for data adds/changes • audit trail/log of all data changes

9. input device options • input decisions • batch VS online • centralized or distributed? • if online, data entry or data capture? • keyboard • mouse • touch screen • graphic input device (light pen…) • voice input device • biological feedback device • terminal • internet workstation • telephone • electronic whiteboard • digital camera • video input • magnetic ink character recognition • scanner / optical recognition • data collection device

10. when considering input options: • costs • security • volumes • accuracy • timing consider: • transaction entry • status update/adjustment • information retrieval for: • when considering user techniques: • menus • form fill • prompt screens • (questions/answer, dialogue) • natural language • GUI

11. input controls GIGO GIGO GIGO GIGO GIGO GIGO GIGO GIGO GIGO GIGO • edits • repetition • business rules • conventions • totals • calculations • visual checks • audit trails • encryption • On error occurrence use: • error messages • error logs • error suspense file

12. output classifications and options printer screen plotter audio e-mail the web fax microform other summary detail turn-around internal external exception

13. questions asked when working with output What’s this about? How recent is the information? Where does it come from? Is all of it here? How current is this? What time period does this information include? How much of the information is included or excluded? Is this an internal or external report? If it’s a turnaround document, how do I use it? Is this detailed information, a summary, or both? What do I do with this? Is the report showing something unusual? Is there bias imposed by sequence, limits or graphics?

14. sample output mockup - printed report