2. Utah School of Computing Design Basics CS5540 HCI Rich R iesen feld Fall 2009 CS5540 HCI Rich R iesen feld Fall 2009 Lecture Set 12

3. Student Name Server Utah School of Computing slide 2 Fall 2009 Thesis HCI intrinsically involves design -“ an interface to …” What does this observation entail? HCI intrinsically involves design -“ an interface to …” What does this observation entail? Design

4. Student Name Server Utah School of Computing slide 3 Fall 2009 Whereas… Design is as old as creativity Intensively studied subject Much is known Let’s tap this understanding and experience! Design is as old as creativity Intensively studied subject Much is known Let’s tap this understanding and experience!

5. Student Name Server Utah School of Computing slide 4 Fall 2009 Design is Ubiquitous Nearly all human activities involve design -Novels, airplanes, murals… -Rescue missions, ascents… -Algorithms, software, interfaces Nearly all human activities involve design -Novels, airplanes, murals… -Rescue missions, ascents… -Algorithms, software, interfaces

6. Student Name Server Utah School of Computing slide 5 Fall 2009 Design Approaches Top down -Mechanical linkages, compilers, software system -Airplane, eg: mission, configuration, weight -Recursive refinement technique Particular as an instance of General -Parametric design Top down -Mechanical linkages, compilers, software system -Airplane, eg: mission, configuration, weight -Recursive refinement technique Particular as an instance of General -Parametric design

7. Student Name Server Utah School of Computing slide 6 Fall 2009 Design Approaches (2) Bottom up -Prototype, gain experience -Abstract principles -Scale up; begin slow Infer General from Particular -Linguistics Bottom up -Prototype, gain experience -Abstract principles -Scale up; begin slow Infer General from Particular -Linguistics

8. Student Name Server Utah School of Computing slide 7 Fall 2009 Bottom_Up ↔ Top_Down Bottom_Up ↔ Top_Down Note: Q E D… Q E D…

9. Student Name Server Utah School of Computing slide 8 Fall 2009 Design Challenges Economics -Make it good and cheap -“Better, faster, cheaper” Constraints -Not design without constraints Economics -Make it good and cheap -“Better, faster, cheaper” Constraints -Not design without constraints

10. Student Name Server Utah School of Computing slide 9 Fall 2009 Critical Choices Design involves making wise “trade-off” -Form v. function -Weight v. durability -Specific and focused v. general and diffuse  Paint v PhotoShop -Etc. … Design involves making wise “trade-off” -Form v. function -Weight v. durability -Specific and focused v. general and diffuse  Paint v PhotoShop -Etc. …

11. Student Name Server Utah School of Computing slide 10 Fall 2009 Design Integrity Clear purpose -Understand the role  Who is user and what is her profile? -Good functional spec  Tasks to accomplish?  Who is user?  Budgets? Clear purpose -Understand the role  Who is user and what is her profile? -Good functional spec  Tasks to accomplish?  Who is user?  Budgets?

12. Student Name Server Utah School of Computing slide 11 Fall 2009 Design Discipline Maintain focus and charge -Refer to specs often Creeping “feature-ism” -“Wheel of re-incarnation” (IES)  Compact cars, portable models, basic models, etc.  Features are NOT free! Maintain focus and charge -Refer to specs often Creeping “feature-ism” -“Wheel of re-incarnation” (IES)  Compact cars, portable models, basic models, etc.  Features are NOT free!

13. Student Name Server Utah School of Computing slide 12 Fall 2009 Design Discipline (2) Sunset the lifecycle Expanded spec New technologies change “design equations” “Just shoot it” -Start over! Sunset the lifecycle Expanded spec New technologies change “design equations” “Just shoot it” -Start over!

14. Student Name Server Utah School of Computing slide 13 Fall 2009 Design Phases/Stages 1.Conceptual  Show that idea can work 2.Preliminary  Sufficient to understand, cost, etc 3.Detail  The “whole enchilada”  Adequate for contracting 1.Conceptual  Show that idea can work 2.Preliminary  Sufficient to understand, cost, etc 3.Detail  The “whole enchilada”  Adequate for contracting

15. Student Name Server Utah School of Computing slide 14 Fall 2009 “Design Intent” Why did the designer do this? What is the function of this component? What was the designer thinking? What are the implications if this is modified? Design Intent is often poorly documented Why did the designer do this? What is the function of this component? What was the designer thinking? What are the implications if this is modified? Design Intent is often poorly documented

16. Student Name Server Utah School of Computing slide 15 Fall 2009 Design History Better at design than documentation Not sensitive to capturing the past Important for the future of a product Need better tools Record the history as well as final result! Better at design than documentation Not sensitive to capturing the past Important for the future of a product Need better tools Record the history as well as final result!

17. Student Name Server Utah School of Computing slide 16 Fall 2009 Documentation Should not be a post-process Capture at time of creation Hard problem, actually -Who should do it? -How should it be accomplished? Expensive -Not always part of deliverable! Should not be a post-process Capture at time of creation Hard problem, actually -Who should do it? -How should it be accomplished? Expensive -Not always part of deliverable!

18. Student Name Server Utah School of Computing slide 17 Fall 2009 Design Conventions Use standards for components Use standards for style Don’t re-invent terms, tech, tools, etc. Make it as straightforward as possible for others who work with you Use standards for components Use standards for style Don’t re-invent terms, tech, tools, etc. Make it as straightforward as possible for others who work with you

19. Student Name Server Utah School of Computing slide 18 Fall 2009 Variant Design Most designs are not really new from the bottom up! Redesign is far more common as an activity than design, actually Make use of the past Use templates, components, previous knowledge, catalogs, etc. Most designs are not really new from the bottom up! Redesign is far more common as an activity than design, actually Make use of the past Use templates, components, previous knowledge, catalogs, etc.

20. Student Name Server Utah School of Computing slide 19 Fall 2009 Lifecycle Design Consider the entire life of a product -Cradle to grave (incl disposal) -Look at lifecycle cost! -Who will maintain? -How long will product live? -What tools are appropriate? -Situations change! Consider the entire life of a product -Cradle to grave (incl disposal) -Look at lifecycle cost! -Who will maintain? -How long will product live? -What tools are appropriate? -Situations change!

21. Student Name Server Utah School of Computing slide 20 Fall 2009 Design for Change The only sure thing about a design is that its requirements will evolve and may change dramatically Build it flexibly, modularly, clearly wrt to intent, etc The only sure thing about a design is that its requirements will evolve and may change dramatically Build it flexibly, modularly, clearly wrt to intent, etc

22. Student Name Server Utah School of Computing slide 21 Fall 2009 Waterfall Model of Design System Concept Spec Sys Req’s Architectural Design Detailed Design Implement, Integrate & Test Deploy & Cash Check

23. Student Name Server Utah School of Computing slide 22 Fall 2009 Waterfall Model of Design System Concept Spec Sys Req’s Architectural Design Detailed Design Implement, Integrate & Test Deploy & Cash Check

24. Student Name Server Utah School of Computing slide 23 Fall 2009 Design Cycle Iterate on the design process repeatedly

25. Student Name Server Utah School of Computing slide 24 Fall 2009 Design Spiral Iterate repeatedly Budget for interaction Throw away early attempts as learning exercises -Steve Coons “I know what to throw out.” Iterate repeatedly Budget for interaction Throw away early attempts as learning exercises -Steve Coons “I know what to throw out.”

26. Student Name Server Utah School of Computing slide 25 Fall 2009 Evolutionary Prototyping Start with initial conceptStart with initial concept Design and implementDesign and implement initial prototype Iterate throughIterate through prototype refinement Complete and releaseComplete and release acceptable prototype Start with initial conceptStart with initial concept Design and implementDesign and implement initial prototype Iterate throughIterate through prototype refinement Complete and releaseComplete and release acceptable prototype

27. Student Name Server Utah School of Computing slide 26 Fall 2009 “ilities” of Design Maintainability Portability Readability Flexibility Testability Etc, etc…. Maintainability Portability Readability Flexibility Testability Etc, etc….

28. Student Name Server Utah School of Computing slide 27 Fall 2009 Complexity “Banana” Complexity space often is shaped like a banana: -Many simple instances -Few complicated instances Complexity space often is shaped like a banana: -Many simple instances -Few complicated instances

29. Student Name Server Utah School of Computing slide 28 Fall 2009 Banana Envelope Number of Items Difficulty of Items Iso-curves for equivalent effort x x x x x x x x

30. Student Name Server Utah School of Computing slide 29 Fall 2009 Design “Reuse” Try to make the parts re-usable for other things or future renovations Use existing parts if available and of adequate quality Try to make the parts re-usable for other things or future renovations Use existing parts if available and of adequate quality

31. Student Name Server Utah School of Computing slide 30 Fall 2009 Design is “team sport” Most designs involve more than one Interfaces are critical, not just components Communications, small granularity exchanges, important Negotiation, compromise part of deal Most designs involve more than one Interfaces are critical, not just components Communications, small granularity exchanges, important Negotiation, compromise part of deal

32. Student Name Server Utah School of Computing slide 31 Fall 2009 Design Views Components may serve different functions -Different designers see different views  Holes v. Elements  Interfaces v. Modules Components may serve different functions -Different designers see different views  Holes v. Elements  Interfaces v. Modules

33. Student Name Server Utah School of Computing slide 32 Fall 2009 Testing and Validation Important stuff! Expensive phase Underdone activity -Alpha testing -Beta testing Important stuff! Expensive phase Underdone activity -Alpha testing -Beta testing

34. Student Name Server Utah School of Computing slide 33 Fall 2009 Design Review Take stock of progress periodically Is design on track? Have it critiqued by a group Take stock of progress periodically Is design on track? Have it critiqued by a group

35. Student Name Server Utah School of Computing slide 34 Fall 2009 Design Evaluation How well does design perform? -Consider all aspects and costs -Were the trade-offs wise? How well does design perform? -Consider all aspects and costs -Were the trade-offs wise?

36. Student Name Server Utah School of Computing slide 35 Fall 2009 Debugging Discipline Early is better: easier and cheaper Product recall is the ultimate “debugging,” and the most expensive, incl product liability Early is better: easier and cheaper Product recall is the ultimate “debugging,” and the most expensive, incl product liability

37. Student Name Server Utah School of Computing slide 36 Fall 2009 Design Safety Consider failure modes What are the consequences of failure? Have they been adequately explored and mitigated? Consider failure modes What are the consequences of failure? Have they been adequately explored and mitigated?

38. Student Name Server Utah School of Computing slide 37 Fall 2009 Design is a Creative Process Respect its needs -Time and patience -Concentration, protracted focus -Freedom to explore new ways  Liberation from past -Individual encouragement and support  Most ideas are not “keepers” Respect its needs -Time and patience -Concentration, protracted focus -Freedom to explore new ways  Liberation from past -Individual encouragement and support  Most ideas are not “keepers”

39. Student Name Server Utah School of Computing slide 38 Fall 2009 Consider Multiple Solutions Competing prototypes -Learn more about merits and liabilities Gain experience “American way (free market)…” -Can help evoke “best effort” Competing prototypes -Learn more about merits and liabilities Gain experience “American way (free market)…” -Can help evoke “best effort”

40. Student Name Server Utah School of Computing slide 39 Fall 2009 Msg: Recognize Design Activity Encourage good design practice Nurture good design through better understanding of its nature -Establish and protect a conducive environment You are designers! Do it well! Encourage good design practice Nurture good design through better understanding of its nature -Establish and protect a conducive environment You are designers! Do it well!

41. Utah School of Computing Design Methodology End End Lecture Set 12