User and Task Analysis

1. User and Task Analysis Lynne Hall

2. Overview • User Profiles and Characteristics • Identifying and representing tasks • Requirements techniques • The Use Case

3. Users “Everybody whose work (?) is affected by the product in some way, including the users of the system’s end product or output even if they never see a single screen.” (Nielsen, 93)

4. The Problem with Work • Many techniques assume a business or commercial context • No longer valid • Major trends • home use • increase in net and web usage • growth in edutainment • rise in e-procurement and e-commerce • changing user populations...

5. Identifying Users • Many different users and stakeholders • Focus on task and reason for use • Use Cases • Task Structures • Constraints • Workflow / Interaction flow • User profiles • main characteristics of users • special needs / requirements of users • relevance of needs

6. Please can I talk to a user... • Use of surrogates or intermediaries • Known to increase likelihood of error • WHY? • Protection of development staff • Control over customer base • Unavailability of real user • Management fear of workforce reaction • User population “too diverse” to identify user representatives [this is a pathetic reason]

7. Use Cases • Descriptions of intended user interactions with the system • Often in written textual form • Provide a basis for task representations • Actors of use cases are frequently users BUT • May not capture all user requirements

8. Indirect Users / Stakeholders • Depends on the definition of user • Trend in HCI to include many user classes • Follows analysis models from business for product development • Incorporated in UML through risk analyses in Elaboration phase • HCI offers a number of techniques to identify users

9. Hutt’s Typology

10. Adapted from Eason (1988) and Smith (1997)

11. Skill level user cube Expert High application knowledge High specific system knowledge Novice IT literacy Low High

12. from Smith (1997)

13. Task Analysis • process oriented models • e.g. DFD • data oriented models • e.g. ERD • (user) task oriented models • diagrammatic techniques e.g. HTA • grammatical techniques e.g. TAG, BNF

14. Task Analysis and the Use Case • Enables diagrammatic representation of use case • Helps to identify system, user and joint tasks • Provides additional medium for • communicating with the user • developing dialogue designs • exploring system functionality

15. Hierarchical task analysis (HTA) • Goals and tasks systematically decomposed into sub-tasks • For multiple sub-tasks, plans describe what order, under what conditions • Assist systematic and natural grouping of sub-tasks in the UI • e.g. in menus • Also for evaluating existing designs

16. HTA for getting to work

17. Competitive Analysis • Anyone else already doing something similar to what your application should do? • If yes, evaluate, analyse, identify • Good points - borrow (if legally possible) • Bad points - redesign • Gaps - your “Unique Selling Point”

18. Creating Version x.xx • Many applications have “sequels” • Microsoft Office has changed significantly • increase in functionality • increase in usability (?) • Games Software • Series of games (ie Final Fantasy - now at 8) • Need for skill transfer / similarity • Needs to be the same proven formula with new games challenges

19. Redesign • Evaluate application • usability testing with users • heuristic evaluation • usage statistics • response to market / environment ?

20. interviews perceptions of system likes and dislikes questionnaires observation of the system in use on site of users doing typical tasks usage logs automatically from system user diaries helpdesk logs bug reports change requests Obtaining Usage Data

22. DEC Rally version 2 • case study of user interface redesign • 4th generation application generator • interactive database applications • originally designed for ease-of-use • proved to be ‘challenging’ in practice • problems only discovered in observation of use at customer sites

23. Initial Information Gathering • used the product themselves • close customer contact • liaison with support and training • bug reports • reviewed competition • developed list of problems to fix

24. Customer/user contact • visits to sites to observe how product was used • initial user interviews • how worked with current product • some users kept a diary of problems • second interviews introduced prototype • user comments • timed and videotaped benchmark tasks

25. Some problems and fixes • complex menu structure • fewer, but larger menus • objects-operations menu to give an overview • lists of values for form filling • showed value names for selection • long names only partially displayed • introduced scrolling & full-screen option • impact of redesign on experts? • compared tasks times, new system faster & better liked

26. Results & conclusions • sales of version 2 above projected levels • usability rated as 2nd most important improvement • context-of-use helped to define problems • e.g. long value names • setting usability targets (e.g. time to do task) key to evaluating solutions • e.g. time to find menu item • methods are complementary: use mixture of theory and data about use in practice