SEG 3210 User Interface Design & Implementation

1. SEG 3210User Interface Design & Implementation Prof. Dr.-Ing. Abdulmotaleb El Saddik University of Ottawa (SITE 5-037) (613) 562-5800 x 6277 elsaddik @ site.uottawa.ca abed @ mcrlab.uottawa.ca http://www.site.uottawa.ca/~elsaddik/

2. Unit D: User Centered Design and Prototyping • System Centered Design • User Centered Design • 3. Case Study: Olympic Messaging System (OMS) • Participatory Design • Design Rationale • UI Prototyping • Paper-based prototypes • Software-based prototypes • Where Does All This Fit Into the Software Engineering Process? • Key Points to Review

3. 1. System Centered Design • What can be built easily on this platform? • What can I create from the available tools? • What do I as a programmer find interesting to work on?

4. 1. System Centered Design

5. 2. User Centered Design • There is no fixed process for HCI design ... • ... Just a series of techniques that have been found helpful • ... And some guidelines to help choose and sequence those techniques • Key principles of user-centered design: • It should involve users as much as possible so they can influence the design • It should integrate knowledge and expertise from all the disciplines that influence HCI design • It should be highly iterative so testing can be done and so users will be satisfied.

6. 2. User Centered Design • Some attributes one needs to be a good UI designer: • A sense of empathy with users • An ability to understand their mental models • An ability to rapidly learn their domain and tasks • Hands-on experience with a wide variety of software. • The more software you see, the more ideas you will have • Analyze all the software you know for malfunctions • This will prevent you from repeating errors! • Familiarity with UI design techniques and guidelines • Golden rule of interface design: “Know The User”

7. 2. User Centered Design • Some critical aspects of the general SE process needed to produce good UIs: (Note: These alone are not enough!) • The goal of all activities must be solving the customer’s problem • Extensive data gathering and analysis must be done to ensure we understand all aspects of the problem. • Well-structured requirements must be reviewed and agreed-to. • Foster a disciplined software engineering process. • Effective regimes must be in place for: • Quality assurance • Configuration management

8. 3. Case Study: Olympic Messaging System (OMS) • Developed by Gould for the 1984 Los Angeles Olympics • Led to the recognition of the term ‘user-centered design’ • Objective: • Develop a system to allow communication among thousands of people during the Olympics • Assumptions: • Telephones will not work as people are constantly moving and participating in events • Non-computer users • To be used by over 20 000 people from kiosks

9. 3. Case Study: Olympic Messaging System (OMS) • Some of the techniques used: • Initial analysis, interviewing, site visits etc. • Usage scenarios prepared • Commented on by many people • Result: Changes made and some functions dropped • User guide prepared • Modified 200 times before final version decided • Simulations constructed and evaluated • Primary purpose: Designing help messages • Result: Discovered need for consistent ‘undo’ and ‘go back’ functionality • Prototype constructed • Result: Many more iterations • ‘Hallway’ method • Soliciting opinions of passers-by • ‘Try-to-destroy-it’ method • Hire hackers to try and break it

10. 3. Case Study: Olympic Messaging System (OMS) • Conclusions: • Focus on users and their tasks early, and keep them central • Measure reactions using prototype manuals and systems • Design iteratively because even highly-skilled designers get it wrong • Usability factors must evolve together and be under the control of one group • The extra work of user-centered design greatly reduces work later on

11. 4. Participatory Design • Problem • intuitions wrong • interviews etc not precise • designer cannot know the user sufficiently well to answer all issues that come up during the design • Solution • designers should have access to pool of representative users • END users, not their managers or union reps! The user is just like me

12. 4. Participatory Design • Users become first class members in the design process • active collaborators vs. passive participants • Users considered subject matter experts • know all about the work context • Iterative process • all design stages subject to revision

13. 4. Participatory Design • Advantages • users are excellent at reacting to suggested system designs • designs must be concrete and visible • users bring in important “folk” knowledge of work context • knowledge may be otherwise inaccessible to design team • greater buy-in for the system often results • Drawbacks • hard to get a good pool of end users • expensive, reluctance ... • users are not expert designers • don’t expect them to come up with design ideas from scratch • the user is not always right • don’t expect them to know what they want

14. Methods for involving the user • At the very least, talk to users • surprising how many designers don’t! • Interviews • used to discover user’s culture, requirements, expectations, etc. • contextual inquiry: • interview users in their workplace, as they are doing their job • Explain designs • describe what you’re going to do • get input at all design stages • all designs subject to revision • important to have visuals and/or demos • people react far differently with verbal explanations

15. 5. Design Rationale • Def: the reasoning behind the design of a software • It could be understood as either: • The process of choosing among design alternatives • A document carefully explaining why certain design decisions are made • Who needs design rationale: • Other developers and maintainers • So the design remains consistent • So old analysis is not repeated • Trainers • So they can answer learners’ questions • Learners may develop a better mental model • Marketing personnel • So they can answer customers’ questions • New staff or new projects • So consistency is maintained

16. Ways people record design decisions • Not at all! • Minutes of meetings • Buried in lengthy narrative • Table with ... • Alternatives considered • Pros and cons of alternatives • Alternative chosen • This approach is reasonable • Diagrams plus tables plus a small amount of narrative • This is ideal but needs computer support to make it fast • We will look at some diagramming techniques

17. Approaches to Document Design • Issue analysis • Determine UI issues to be resolved and options for their resolution • Design space analysis • exploration of a space of alternatives • For several options, determine goals they would achieve • Claims analysis • Look for ‘claims’ explicit or implicit in a design decision • Reason about whether the claim is legitimate • e.g. A design has single-letter commands • Implicit claim: This is faster to use • Is it really? Document reasoning

18. Issued-Based Analysis • Originated with the IBIS system in 1970: (Issued-Based Information Systems) • PHI is a more modern variant (Procedural Hierarchy of Issues) • Steps: • Build a hierarchy of issues (‘questions’) • Sub-issues are issues that, if resolved, would help solve higher level issues • Identify high level (prime) issues • Repeatedly identify sub-issues breadth-first • Resolve issues starting at the bottom level • List options (positions or answers) i.e. ways of dealing with each issue • List arguments for and against each option • Choose the best answer • Leave the hierarchy, options, arguments and chosen option in the design documentation!

19. An example issue hierarchy for a library system How to go to previous screen How to exit? How to go to higher level? How to exit system? How should the user navigate the Library? How to get more detail? How to get related books?

20. Design space analysis • Exploration of space of alternatives • Better quality because designer will have explored more alternatives • And documents them at the same time • Use of QOC notation • Questions: highlight issues that must be considered • Options • Criteria: argue for or against various alternatives • Steps to make a decision about an issue: • List the options as in issue analysis • List positive criteria (benefits gained, or goals achieved by choosing one or more options). • Show which criteria argue for or against each option • Pick the option that best meets goals

21. An example navigation problem: Mechanisms are needed to move... A: Within items on a screen B: To and from a greater level of detail C: To and from related screens at the same level of detail Options Option 1 A: tab / back tab B: right arrow / left arrow B’: left arrow C: + / - Option 2 A: tab / back tab B and C: return / escape Option 3 A: down arrow or tab / up arrow or back tab B: return / escape B’: select ‘higher level’ (A) then return (B) or escape C: select ‘up’ (A) then return (B) / select ‘down’ then return Design space analysis B ? B’ A C

22. Design space (omitting negative criteria)

23. Using Design rationale • Design rationale is critical in UI design because: • There are usually numerous alternatives • Unless analysis is systematic, one may • ... pick a suboptimal alternative • ... not even think of one or more alternatives • Alternatives depend on the context • If the context changes, one can quickly study the reasoning to see if a system change is needed • Design rationale is good for both • Actively designing • Recording (documenting) the design

24. Using Design rationale • As a minimum, use design rationale when: • There is deliberation over a decision • Reviewers raise issues • Opinion war is looming • Accommodation is necessary • Special knowledge is applied • Testing reveals shortcomings • Uncertainty remains • A kludge had to be made • Use issue and design space analysis in a brainstorming environment • And record the results • Analyze all claims (evaluate them) • And record the results

25. 6. UI Prototyping • UI Prototyping involves a scaled down analysis-design-evaluate cycle • It is an analysis technique • Two key kinds of UI prototypes: • Paper based • Quick and inexpensive • Stimulates ideas in a brainstorming environment • Software based • Demonstrate functionality and usability • A simulation of the eventual system

26. Why is it essential to prototype the UI? • With technical design documents alone ... • It is hard to imagine ramifications of design decisions • It is hard to represent interactions in a complete, consistent and readable way • The system may have high functionality with low usability • People are much more likely to get the functional aspects of a system right up front • The UI is where most complaints will come from • It is too late to start fixing it once the product is built

27. 7. Paper-based prototypes • Paper-based prototypes • a paper mock-up of the interface look, feel, functionality • “quick and cheap” to prepare and modify • Purpose • brainstorm competing representations • elicit user reactions • elicit user modifications / suggestions

28. Computer Telephone Last Name: First Name: Phone: Place Call Help Paper-based prototypes • Sketches • Drawing of the outward appearance of the intended system • Crudity means people concentrate on high level concepts • But hard to envision a dialog’s progression

29. Paper-based prototypes • Storyboarding • a series of key frames • originally from film; used to get the idea of a scene • snapshots of the interface at particular points in the interaction • users can evaluate quickly the direction the interface is heading

30. Help Screen Computer Telephone Computer Telephone You can enter either the Call by person's name or their Establishing Last Name: Greenberg Last Name: Help-> name-> connection-> number. Then hit the First Name: First Name: place button to call them Phone: Phone: Place Call Help Place Call Help Return Computer Telephone Computer Telephone Call Call Dialling.... Connected Last Name: Greenberg Last Name: Greenberg connected... completed... First Name: First Name: Cancel Hang up Phone: Phone: Place Call Help Place Call Help Storyboard of a computer based telephone

31. Paper-based prototypes • Pictive • plastic interface for collaborative technology initiatives through video exploration” • design is multiple layers of sticky notes and plastic overlays • different sized stickies represent icons, menus, windows etc. • interaction demonstrated by manipulating notes • contents changed quickly by user/designer with pen and note repositioning • session is videotaped for later analysis • usually end up with mess of paper and plastic!

32. Paper-based prototypes • Pictive • can create pre-made interface components on paper • eg, these empty widgets were created in JBuilder/visual basic and printed out: buttons menu alert box combo box list box tabs entries

33. Some ideas of paper prototyping • Draw diagrams on cards for each screen, window, menu • Don’t worry about being precise; sketch roughly • Draw different versions of the cards so you can experiment with which is best • Experiment walking through various tasks (‘scenarios’) • Do the above in a brainstorming environment with users and colleagues • Keep the design space open as long as possible! • Commit to a particular UI as late as possible • Storyboards are faster and cheaper than computer prototypes

34. 8. Software based prototype • Actually works • Must be built quickly and cheaply • Is an integral part of user-centered design • Evaluation and modification are fundamental • The code is generally thrown away • But the design is kept! • In incremental and evolutionary prototyping the code may be kept • But watch out for unmaintainable code • A requirements animation: • Is a less functional kind of prototype • A demonstration of the system that acts like a ‘movie’ • walks through interactions • Can be stepped through to illustrate tasks • Can be quick to set up

35. What parts of the UI should you prototype? • As much as possible, but emphasize: • The top 20% of tasks • That will usually consume 80% of a user’s time • Those aspects of the UI that are considered ‘unusual’ or ‘problematic’ • E.g. Screens where you have unusual widgets • Anything safety-critical, even if only used occasionally

36. Approaches to limiting prototype functionality • Vertical prototypes • includes in-depth functionality for only a few selected features • common design ideas can be tested in depth • Horizontal prototypes • surface layers includes the entire user interface with no underlying functionality • a simulation; no real work can be performed • Scenario • scripts of particular fixed uses of the system; no deviation allowed

37. Approaches to integrating prototypes and product: • Throw-away • prototype only serves to elicit user reaction • creating prototype must be rapid, otherwise too expensive • Incremental • product built as separate components (modules) • each component prototyped and tested, then added to the final system • Evolutionary • prototype altered to incorporate design changes • eventually becomes the final product

38. Presenting SW-based prototype • Painting/drawing packages • draw each storyboard scene on computer • neater/easier (?) to change on the fly than paper • a very thin horizontal prototype • does not capture the interaction “feel”

39. Control panel for pump 2 Control panel for pump 2 DANGER! coolant flow 45 % coolant flow 0 % next drawing retardant 20% retardant 20% (on mouse press over speed 100% speed 100% button) Shut Down Shut Down Presenting SW-based prototype • Scripted simulations and slide shows • encode the storyboard on the computer • created with media tools • scene transition activated by simple user inputs • a simple horizontal and vertical prototype • user given a very tight script/task to follow • appears to behave as a real system • but script deviations blows the simulation

40. Computer Telephone Last Name: Greenberg Computer Telephone Computer Telephone Computer Telephone First Name: Phone: Last Name: Last Name: Last Name: First Name: First Name: First Name: Place Call Help Phone: Phone: Phone: Place Call Place Call Place Call Help Help Help Computer Telephone Computer Telephone Dialling.... Connected Last Name: Greenberg Last Name: Greenberg First Name: First Name: Help Screen Cancel Hang up Phone: Phone: You can enter either the person's name or their Place Call Help Place Call Help number. Then hit the place button to call them Return Presenting SW-based prototype Help- Type name and place call

41. Constructeurs d’Interfaces • Outils qui permettent à un concepteur de présenter les gadgets logiciels (widgets) communs • Mode de construction • changer les attributs des objets • Mode de test: • Les objets se comprotent comme s’ils étaient dans les situation réelles • Excellent pour montrer l’apparence et les sentiments • un prototype horizontal plus large • mais contraint à la librairie de widget • Les fonctionnalités verticales sont ajoutées sélectivement • En programmant

42. L'évaluation d'un prototype fournit l'information sur • Séquences de fonctionnalités et des opérations • Assister l'analyse des tâches • Certains systèmes créent malheureusement des nouvelles tâches pour les usagers! • e.g. le temps passé à organiser des fichiers, convertir les formats, traduire les schémas de codage • La convivialité de l’apparence et les sentiments • Les symboles que les usagers peuvent reconnaître • Ou la disposition ou les messages causent une confusion etc. • Les besoins du support de l’usager • Ou l’aide et l’entrainement sont necessaires

43. Quleques obstacles pour un prototypage efficace • Ceci prend du temps • Souvent il est entièrement omis ou l’évaluation est dépassée • Mais l'évaluation lui donne 70% de sa valeur • Beaucoup de gérants n’ont pas l’expérience requise • La gestion peut faire penser que c’est vrai • “La question n'est pas d’établir un système pilote et le jeter. Vous ferez cela. La question est de projeter à l'avance d’en construire un jetable” - Brooks • Solution: entraîner les gérants • Il est difficile de s'adapter dans un processus contractuel • Particulièrement quand le contrat doit mettre en application des spécifications données • Solution: les Contrats doivent être basés sur “la résolution du problème”

44. Conclusions à propos du prototypage • Planifier assez de temps pour prototyper les aspects clés de n’importe quel système • Évaluer les prototypes de façon appropriée • Tenir compte que le prototypage seul ne vous donnera pas toutes les réponses • D’autres techniques sont nécessaires pour générer les idées pour le prototype: • Analyse des tâches • Modélisation conceptuelle • “Storyboarding” • Raisonnement de conception • Il manque les issues non fonctionnelles telles que la fiabilité et la sûreté. • Considérez les produits de concurrence précédents en tant que prototypes additionnels • Mais vous devez compenser le prototype de toutes les différences ou déviations de ces derniers !

45. 9. Ou s’adapte tout ceci dans le processus du génie logiciel? • En développant des interfaces usagers, l'analyse et la conception sont naturellement mélangées • Il y a trois genres de conception: • Conception architecturale • comment découper le système en couches • Conception d’interface • comment faire fonctionner le système avec la tâche et le modèle conceptuel • Conception détaillée • comment appliquer les écrous et les boulons physiques

46. Functional Prototyping & Other Techniques Functional / OO Analysis Architectural Design (Splitting system into layer) API Spec. UI Spec. Detailed Design Where does all this fit into the SW Eng. process? General Requirements Gathering, Scoping and Objective Setting UI Analysis & Design

47. Pensées au sujet des caractéristiques • L’importance des caractéristiques: • Tenez compte des accords contractuels ou partager avec les membres d'équipe • Formez la base pour des conceptions détaillées efficaces • Forcer la pensée détaillée • mettez souvent les problèmes cachés en évidence • Il y a un avancement pour rendre des caractéristiques mathématiquement formelles • Ceci est encore non-réalisable pour les spécifications des IU

48. Pensées au sujet des caractéristiques Séparez clairement les composants suivants des spécifications(préparation rigoureuse en parallèle): • Spécifications formelles de l‘API et des couches inférieures • L‘API doit être établi un peu en avant de Spécifications d’IU. • Décrire les données et les opérations de façon abstraite et précise • Un prototype n’est pas suffisant • Spécification de l’IU • Peut être le résultat de la conception d’IU ou plus formel • Dépend en quelque sorte des spécifications de l’API mais affecte aussi ce qui va être dans l’API. • décrit • “look”: l’apparance de l’IU • sensation : détails des interactions

49. Pensées concernant la conception de l’API • Ce qui doit être fait au niveau de la couche d’IU: • Compostion et affichage des sorties • Division en écrans; navigation à travers les écrans • Interprétation des évenements • Menus, boutons d’action et “hotkeys” • défilement, restructuration etc. • L’aide • Ce qui doit être fait aux couches inférieures • (i.e. communicant via l’API) • Actions effectuées sur les données • Requêtes pour les données • Requêtes des informations concernant l’état du système ou l’objet • Charger et sauver les fichiers • Génération de la plupart des structures d’erreurs • Quelques systèmes peuvent manipuler les « codes » mais ceci bloque les messages fortement utilisables

50. Charactéristiques de l’API • L’API doit servir l’interface usager • Penser en fonction des commandes qui peuvent servir l’usager à accomplir sa tâche • S’assurer que les besoins des E/S de l’IU sont servis via l’API • L’API doit permettre la flexibilité • Replacement de l’IU comme les améliorations sont exigées • IU alternatif (e.g. accès en ligne, ligne de commande) • Tests automatiques • Remplacement des couches inférieures • Les remplacements fournissent le même API • En dépit de ce qui précède, l‘API devrait être aussi simple que possible