CS3724 Human-computer Interaction

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Buddy Watson
6 years ago
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2 Topics Connections of user interaction development to software engineering Development activities in the usability engineering life cycle Usability management User interface development team

3 System feasibility Typical Software Engineering LC The Waterfall Model Software plans requirements Product Detailed Code Integration Implementation Operations

4 The Process of User Interaction Development Connections of user interaction development to software engineering All these figures depict communication paths, not temporal ordering of activities Distinction between implementation Start with basic software engineering concept: Software Software implementation Spec'ns Constraints

5 Major reconsiderations The Process of User Interaction Development Adding systems analysis, testing, problem (application) domain Test plan, criteria Req'ts Req'ts Spec'ns Pgms Systems analysis Problem domain Constraints problems Software Constraints problems Software implementation Constraints problems Errors, bugs Software testing Main feedback: flaws, errors, modifications

6 The Process of User Interaction Development Analogous activities for user interface development Test plan, usability spec'ns Systems analysis Interface req'ts, usability spec'ns User interface interaction Constraints problems Software requirements User interface software Constraints problems Pgms Errors, bugs Software implementation spec'ns User interface software implemen- Contatiostraints problems Userbased evaluation of interface software Main feedback is due to low usability: flaws, errors, modifications

7 The Process of User Interaction Development Connecting the processes together adding rapid prototyping

8 Req'ts Req'ts Spec'ns Applica- Pgms Applica- Problem tion tion domain software software implemen- Con- Contation Errors, Constraintstraints bugs straints problems problems problems Systems Main feedback: flaws, errors, modifications analysis Major reconsiderations Interface req'ts, usability spec'ns User interface interaction Constraints problems Constraints problems Software requirements Software implementation spec'ns User User interface interface software software implemen- Contatiostraints problems Pgms Errors, bugs Usability Main feedback is due to low usability: spec'ns flaws, errors, modifications Test plan, usability spec'ns Userbased testing evaluation of interface noninterface software Rapid prototyping Formative userbased

9 The Process of User Interaction Development The rest of this course is about just this part: Systems analysis Interface req'ts, usability spec'ns Constraints problems User interface interaction Usability spec'ns Rapid prototyping Formative userbased

10 Iterative, evaluation-centered process model for interaction development New life cycle concept comes from: The waterfall model movement toward completion Star (Hartson & Hix, 1989) evaluation centered LUCID (Cognetics, Inc.) development activities Boehm s Spiral Model iteration New work by Helms & Hartson (2001) put it together

11 Star (Hartson & Hix, 1989) Evaluation centered

12 Boehm s spiral model-evolution through iteration

13 Cumulative Cost Boehm s spiral model abstracted Determine objectives, alternatives, constraints Evaluate alternatives, identify, resolve risks Commitment Review Plan next phases Develop, verify nextlevel product

14 Spiral model adapted

15 Spiral unwound

16 Spiral unwound stretched out

17 Waterfall with whirlpools

18 Direction of evolutionary advancement Wheel User/task model Usage scenarios Screen s Connecting into Wheel, for intercycle iteration Product concept Global evaluation hub Lo-fi prototyp Close down Hi-fi prototyp Operational system Deployment Integration

19 Life cycle=iterative configuration of cycles (each associated with a stage/form of the product) Example: System analysis model, scenarios screen s, lo-fi prototype, hi-fi prototype, software production & integration Cycle is a sequence of four development activity types: Analyze Design Build Evaluate

20 Product form out The Wheel Usability Engineering Cycle as sequence of four types of development activities Design Product form in Analyze Cycle of activities Implement Evaluate

21 Technique Technique Project role Zoom in on details of a generic cycle activity Technique selection criteria Product form in Activity role Activity type/ instance Product form out Work products Tools/templates Relationships with other activities Work products Common database

22 Choose a technique for each activity type in each cycle

23 Shows how each activity type is assigned a technique, the role of the person doing the activity, support tools, documentation Example: In scenario screen cycles, walk through is used as evaluation technique Basic Principles Process is product oriented Products evolve through cycles (cycles named for product forms)

24 Each cycle is iterative Each cycle contains same activity types Each cycle is evaluation-centered Work products (documentation) evolve over cycles Process can be viewed at different levels Process, cycle, activity, documentation

25 Any part of the process is an instance of what is possible Pick choose cycles, activities, iterations to meet schedule, budget, management style Integrate with software engineering development process Validated by Helms & Hartson (2001) in e- commerce start-up company

26 Any part of process is instance of what is possible Developers include their favorite UE methods techniques Omit activities, cycles, iterations indicated by management, budget, schedule, project scope, team composition Can be different every time

27 Usability Management The control mechanism for the iteration Control involves: Establishing usability specifications Evaluating against usability specifications Performing impact cost/benefit analyses

28 Usability Management Deciding on changes to make to interaction Deciding when to stop iterating Same process can be applied to develop user documentation or training course

Meet the User Interface Development Team Roles on user interface development team Note: Different roles, but not necessarily different people User interaction er (or usability engineer or

29 Meet the User Interface Development Team Roles on user interface development team Note: Different roles, but not necessarily different people User interaction er (or usability engineer or usability specialist) Evaluator (or facilitator) User (/or user representative) Software engineer /or programmer Technical writer Graphic er Application domain expert (also called subject matter expert)

Topics. CS5714 Usability Engineering. Typical Software Engineering LC. An Iterative, Evaluation- Centered Life Cycle For Interaction Development

Topics. CS5714 Usability Engineering. Typical Software Engineering LC. An Iterative, Evaluation- Centered Life Cycle For Interaction Development CS5714 Usability Engineering An Iterative, Evaluation- Centered Life Cycle For Interaction Development Copyright 2004 H. Rex Hartson Deborah Hix Topics Connections of user interaction development to engineering