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Ch 4: Discovery Yonglei Tao School of Computing & Info Systems GVSU.

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Presentation on theme: "Ch 4: Discovery Yonglei Tao School of Computing & Info Systems GVSU."— Presentation transcript:

1 Ch 4: Discovery Yonglei Tao School of Computing & Info Systems GVSU

2 2 Discovery Collection Interpretation Documentation

3 3 Exploring the Work Domain Diverse design projects  new designs  redesign  innovative devices Different work domains  tracking inventory, customer orders, billing, and websites Various stakeholders  Primary, secondary, facilitator, indirect

4 4 Organizing the Process What/How  What activities are involved and how are they done? Where/When  What impact of physical location is on the work flow? Who/Why  Who is involved  Why they are involved  Their role in the present work flow  How they may respond to any changes implemented

5 5 Collection - Methods

6 6 Collection - Elicitation Eliciting info from various stakeholders  Direct Interviews Focus groups  Indirect Corporate documentation Logs and notes Questionnaires

7 7 Interpretation User Analysis  Primary Stakeholder Profiles Task Analysis Storyboarding Use Cases

8 8 User Analysis Identification of User's Needs + Implementation = Successful User Interface Design

9 9 Understand People Must know how people work in order to design for them  Learn by recognition, not recall  Remember things in related groups  Have different ways of learning and communicating  Have different strengths and limitations  Like to be in control  Want to get their work done

10 10 Know Your Users Skills Training and support availability Frequency of use Vocabulary Environment issues

11 11 User Category Novice / Occasional Frequent / Intermediate Expert

12 12 Novice/Occasional Users Expect intuitive, easy to use application Do not want to rely on training or documentation May need support for multiple input methods Big learning curves are unacceptable

13 13 Frequent/Intermediate Users Perform routine tasks  Such as transaction processing applications Need quick response Focus on quickness of data entry and review

14 14 Expert Users Very familiar with software applications and environments Like to explore May expect higher degree of functionality Comfortable with multi-windowed systems

15 15 User Skill Level Evolution Skills of an application user evolves over a period of usage Novice Intermediate Expert

16 16 Different Types of Applications Life-critical systems  Air traffic control, nuclear reactors, power utilities, police & fire dispatch systems Industrial and commercial uses  Banking, insurance, order entry, inventory management, reservation, billing, and POS Office, home, and entertainment applications  Word processing, electronic mail, computer conferencing, and video game systems, educational packages, search engines, mobile device, etc. Exploratory, creative, and cooperative systems  Web browsing, search engines, artist toolkits, architectural design, software development, music composition, and scientific modeling systems Social-technical systems  Voting, health support, identity verification, crime reporting

17 17 Outlook Express

18 18 Visual Basic.Net

19 Blackboard 19

20 20 User Analysis Matrix

21 21 Primary Stakeholder Profiles Used to define the target user  Context of use  Cognitive ability  Physical ability  Individual profile

22 22 Context of Use

23 23 Example of Context of Use

24 24 Cognitive Ability Profiles

25 25 Physical Ability Profiles

26 26 Individual Profiles

27 27 Task Analysis Understanding requirements  Determine tasks users perform  Document how users perform tasks Deriving user interface design Evaluating user experience  Involve physical and cognitive actions Techniques  Hierarchical Task Analysis (HTA)  Storyboarding  Use cases

28 28 Task Decomposition Identify the process Describe the steps Include the following:  Reasons for the actions  People who perform the actions  Objects they need to use and info they need to know

29 29 An HTA Diagram Borrow a book from the library go to the library find required book retrieve book from shelf take book to counter 3214 0 access catalog access search screen enter search criteria identify required book note location plan 0: do 1-3-4. If book isn’t on the shelf expected, do 2-3-4. plan 2: do 2.1-2.4-2.5. If book not identified from information available, do 2.2-2.3-2.4-2.5 2.12.22.32.42.5

30 30 Textual Representation of HTA 0.In order to borrow a book from the library 1.go to the library 2.find the required book 2.1 access library catalogue 2.2 access the search screen 2.3 enter search criteria 2.4 identify required book 2.5 note location 3.go to correct shelf and retrieve book 4.take book to checkout counter Plan 0: do 1-3-4. If book isn’t on the shelf expected, do 2-3-4 Plan 2: do 2.1-2.4-2.5. If book not identified do 2.2-2.3-2.4

31 Task Sequence A plan is to describe in what order and under what conditions subtasks are performed Types of plan fixed sequence-1.1 then 1.2 then 1.3 optional tasks-if the pot is full 2 wait for events- when kettle boils 1.4 cycles-do 5.1 5.2 while there are still empty cups time-sharing-do 1; at the same time... discretionary-do any of 3.1, 3.2 or 3.3 in any order mixtures-most plans involve several of the above

32 32 Relative Task Frequencies

33 33 HTA – Understanding Requirements Start with a user goal and identify the main tasks for achieving it Break a task down into subtasks, then sub- sub-tasks and so on  Focus on physical and observable actions  Determine atomic actions Group tasks as plans that specify how they might be performed in practice

34 Scenarios for “Bake a Cake”

35 “Bake a Cake” (Cont.)

36

37 HTA - Deriving UI Design 37

38 Evaluating User Experience 38

39 An Example Some years ago the US telephone company NYNEX were intending to install a new computer system to support their operators. Before installation a detailed GOMS analysis was performed taking into consideration the cognitive and physical process involved in dealing with a call. The task analysis was used to determine the critical path, and hence the time to complete a typical task. It was discovered that rather than speeding up operations, the new system would take longer to process each call. The new system was abandoned before installation, leading to a saving of many millions of dollars. 39

40 40 Storyboarding Using a series of pictures to describe a particular process or work flow  Study existing work flows or generate requirements.  Facilitate task decomposition  Brainstorm alternative ways of completing tasks Used early in design

41 Use Cases A story about how a user will use the system to do what one needs  Defines a sequence of interactions between one or more actors and the system  Describes requirements in context  Focuses on functional requirements Writing use cases is also a requirements elicitation process 41


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