1. Iterate (Requirements, Design) IMD07101: Introduction to Human Computer Interaction Brian Davison and Tom McEwan 2011/12

2. Content The relationship between requirements and design Process models Functional and non-functional requirements Use cases Coursework general feedback

3. Requirements and design Iterate: repeat until done DesignRequirements

4. Structured process (the old way) Requirements specification Analysis Design Implementation Testing

5. Agile process (the new way) Implement prototype Evaluate prototype Plan Design Brief Product

6. Establishing requirements Gathering Generation Elicitation Engineering Initial data collection –Interviews –Questionnaires –Observation –Think aloud protocols Refining requirements –Review prototypes –Walk-throughs –Focus groups

7. Types of requirement Functional requirements –Define what the system must do –Can be tested –Either works or not Non-functional requirements –Define all other requirements –Include usability goals, performance goals, etc. –Need to be evaluated –May depend on users' preferences

8. Example: personal agenda Functional Store/alter/delete appointments Deliver reminders Synchronise with Google calendar Non-functional Runs on Android, iPhone and Windows phone Personalised theme Multilingual Under 2s start up Operates without Internet Attractive to UK teenagers

9. Use cases Describe functional requirements "Units of interaction" Define interactions between actors and the system Personal agenda Owner System Store appointment Alter appointment Delete appointment Deliver reminder Synchronise

10. Detailed use cases UC1: Store appointment Actor: Owner 1.Choose day 2.Choose time 3.Enter detail 4.Enter duration 5.Save UC2: Delete appointment Actor: Owner 1.Locate appointment 2.Delete UC3: Deliver reminder Actor: System Trigger: system time = appt. time 1.Display appointment detail 2.Sound audible alarm Exception: 1.Sound turned off

11. Relationships between use cases Personal agenda Owner System Store appointment Alter appointment Delete appointment Deliver reminder Synchronise Manage appointment Find appointment >

12. Defining NFRs CategoryRequirement CompatibilityRuns on Android, iPhone and Windows phone UsabilityPersonalised theme AccessibilityMultilingual PerformanceUnder 2s start up ReliabilityOperates without Internet UsabilityAttractive to UK teenagers

13. Design principles (Benyon) Visibility Consistency Familiarity Affordance Navigation Control Feedback Recovery Constraints Flexibility Style Conviviality

14. Techniques Implement prototype Evaluate prototype Plan Design Brief Product Personas Scenarios Storyboards Sketches Prototyping Interviews Focus groups User testing Interviews Questionnaires Observation

15. Short break

16. Coursework In 1000 words (+/- 10%), explain how design techniques can be used to enhance the usability and accessibility of an interactive system. You must discuss examples that you have seen in lectures, tutorials and practicals in this year's delivery of the module. Make sure that you draw appropriate distinctions between principles (what to do) and techniques (how to do it).

17. Important elements Design techniques –Methods for doing design –PACT analysis –Brainstorming –Personas –Scenarios –Storyboarding Usability Accessibility Examples

18. Possible structure Introduction Definitions –Usability –Accessibility Design techniques –General benefits –PACT analysis –Personas –Scenarios –Storyboarding Conclusion State purpose of report Set the context For each example technique, explain the benefits for usability and accessibility and provide examples

19. Common errors 1 No mention of design techniques Failed to distinguish between techniques for design and others Failed to distinguish between techniques and principles Failed to explain the link between a technique and the usability and accessibility of the final product

20. Common errors 2 Description of features rather than process Majority of report spent on definitions High-level recommendations In my opinion... "There are many techniques..." Poor use of terminology – eg HCI