ISDE Revision Topics 2012

1. ISDE Revision Topics 2012 ISDE Revision Topics 2012 Compiled by Sheila Cassidy-Allan using J Burns slides

2. Exam Details • Date – Thursday 24 May • Time – 9am • Duration 2hrs • Suggested time to read scenario and questions 30 minutes • Answer 2 of the 3 questions available

3. ISDE Review • Goals of HCI • Safety • Effectiveness • Efficiency • Usability • Appeal • Justify Trade offs

4. User Centred Activities User Analysis Prototyping Usability Specifications Evaluation Task Analysis

5. User Characteristics • Physical Differences • General Differences • Intelligence • Motivation • Knowledge • Education • Cultural Differences

6. User characteristics: physical differences • Age (use larger fonts for older people) • Vision limitations, such as colour blindness • Other physical limitations that might restrict movement • Small children don’t have good fine-muscle control: see big buttons on next slide ISDE 2009

7. Frequent Uses/Infrequent User? • How can we design our interface to suit both types of users?

8. System Related User Characteristics • What characteristics can you expect of the users of your interface? • frequency of use • discretion to use the system • knowledge of the task which the system will support • knowledge of computers • experience of other similar systems • general abilities, e.g. literacy, vision • attitude towards computers (and your system) • existing skills (keyboard, mouse) ISDE 2009

9. Task Analysis • How is it used? • How does it inform our design? • Task sequence – in what order • Task Frequency – how often • Task Criticality – how important • Task Allocation – who or how

10. Design Guidelines (Heuristic) use simple and natural dialogue sequences speak the users language minimise user memory load be consistent provide feedback provide clearly marked exits provide shortcuts provide good error messages prevent errors

11. Ambiguous Design • What is this? • Give an example

12. Discretionary User? • What is this? • Give an example

13. UCD Activities • Prototyping • What are the key techniques? • Horizontal /Vertical • High & Low Fidelity prototypes examples? • Throwaway • Evolutionary • Incremental and requirement gathering • + and – of each

14. What is a prototype? • In interaction design it can be (among other things): • a series of screen sketchesa storyboard, i.e. a cartoon-like series of scenes a Powerpoint slide showa video simulating the use of a systema lump of wood (e.g. PalmPilot)a cardboard mock-upa piece of software with limited functionality written in the target language or in another language

15. General Features of Prototyping • Enables the designer to quickly build or create examples of :- • The data entry form • The menu structure and order • The dialogue styles • Error messages • Should be inexpensive to develop – intention is to discard/modify it • Should not require programming skills

16. What to prototype? • Work flow, task design • Screen layouts and information display • Difficult, controversial, critical areas

17. Low-fidelity Prototyping • Uses a medium which is unlike the final medium, e.g. paper, cardboard • Is quick, cheap and easily changed • Examples: sketches of screens, task sequences, etc ‘Post-it’ notes storyboards ‘Wizard-of-Oz’

18. Paper Based Prototyping • Paper based prototypes • These have no functionality but can still be useful for:- • Generating ideas • Gaining insights into what the user might want or is thinking Eg a paper based design of a data entry screen • Storyboards and Snapshots • using “film-scripting” techniques to visualise interactions between users and the system • This is very quick and cheap

19. Storyboards • Often used with scenarios, bringing more detail, and a chance to role play • It is a series of sketches showing how a user might progress through a task using the device • Used early in design for example check availability or book What are the stages?

20. High-fidelity prototyping • Uses materials that you would expect to be in the final product. • Prototype looks more like the final system than a low-fidelity version. • For a high-fidelity software prototype common environments include Macromedia Director, Visual Basic, and Smalltalk. • Danger that users think they have a full system…….see compromises

21. Aims of Prototyping in Software The aim of prototyping is to resolve uncertainty about • functional and user requirements • operation sequences • user support needs • required representations • “Look and Feel” of the interface • appropriateness of the design

22. Software Prototyping • A software prototype will be a version of the proposed system with limited functionality • Will differ from the final system in terms of • Size, reliability robustness & completeness A software prototype • is “executable” • can be thrown away, or evolve • may serve many different purposes • should be “quick and dirty” (and cheap!) • is an integral part of user-centred design approaches based on evaluation/modification

23. Collecting Users Opinions • Questionnaires • “open” (free form reply) or “closed” (answers “yes/no” or from a wider range of possible answers) • latter is better for quantitative analysis • important to use clear, comprehensive and unambiguous terminology, quantified where possible • e.g., daily?, weekly?, monthly? Rather than “seldom”, “often” and there should always be a “never” • Needs to allow for “negative” feedback • All Form Fill-in guidelines apply!

24. Components of a usability specification • Statement of the usability goal • Statement of the usability attribute • Statement of the criteria which will represent attainment of the specification • Now level • Worst case • Planned level • Best case • Statement of which set or subset of users the specification applies to • A statement of preconditions for the measurement

25. Sample specification • Usability Goal: Users can quickly obtain a balance from an ATM • Attribute: Time • Measuring method: Observe and record Time taken by users to obtain balance • Now level: 30 secs • Worst case: 25 secs • Planned level: 20 secs • Best case: 15 • User class: All • Preconditions: Users are familiar with ATMs

26. Usability Engineering What is UE? You should now be able to write a specification! What are the components of a usability Specification?

27. Interaction Elements Icons Sound/ Music speech Video/Pictures Text Colour What are some of the key design issues surrounding each of these?

28. The Primary Styles of Interaction • Q & A • Menu selection • Form fill-in • Command language • Direct manipulation • Natural language/Anthropomorphic

29. Advantages and Disadvantages of Menus • Advantages • shortens learning curve • reduces keystrokes • structures decision-making • permits use of dialogue-management tools • allows easy support of error-handling • Disadvantages • imposes danger of deep-nested menu hierarchies • may slow frequent users • consumes screen “real estate” • requires rapid display rate

30. Advantages and Disadvantages of Form Fill-in • Advantages • simplifies data entry • requires modest training • makes assistance convenient • permits use of form-management tools • Disadvantages • consumes screen “real estate”

31. Q & A • Simple interaction style • Users respond to series of questions • Input is usually Y/N or a particular single input • Print whole document? • No of pages to print? • No of copies

32. Reasons for Evaluation • Understanding the real world • particularly important during requirements gathering • Comparing designs • rarely are there options without alternatives • valuable throughout the development process • Engineering towards a target • often expressed in the form of a metric • Checking conformance to a standard Evaluation J T Burns Feb 2010

33. Evaluation Techniques • How applied? – how long, amount of errors (usability spec) • Techniques for doing evaluations • Question design • appropriate questions • Justification

34. Observation and Monitoring - Direct Observation Protocol • Usually informal in field study, more formal in controlled laboratories • data collection by direct observation and note-taking • users in “natural” surroundings • quickly highlights difficulties • Good for tasks that are safety critical • “objectivity” may be compromised by point of view of observer • users may behave differently while being watched (Hawthorne Effect)

35. Heuristic Evaluation • Useful where method of operation is not fully predictable and where user might not be a complete novice • Relies on a ‘team’ of evaluators to evaluate the design • Each individually critiques the design –4/5 evaluators discover 75% of problems • Set of Design Heuristics (general guidelines) is used to guide the evaluators – Prevent errors Evaluation J T Burns Feb 2010

36. Important Lectures to revise • Process of Interaction –wk 4 • Prototyping – wk 7-8 • Usability Engineering – wk 8 • Evaluation – wk 14&15