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Prototyping
After conducting User and Task Analysis and developing a plan it is time to prototype
Also prototype proposed changes to site
Prototyping
Goals:Observe aspects of web siteEvaluate design ideasConsider alternatives
Why Prototype?
Can’t test until you have a siteBut, implementing a site is:
Expensive Time consuming
Result: a paradox
Prototyping
Breaks this paradoxAllows evaluation of designs earlyTechnique not a specific tool
Prototyping
Programmers want to program not design
HCI people want to testPrototyping allows a compromiseSimilar to artillery method of Ready-
Aim-Fire
Ready Aim Fire
Types of Prototypes
Evolutionary - complete enough to become site
Revolutionary or Throwaway - prototype guides design but is thrown away
Horizontal Prototype
Little depth of functionalityBroad designHomepagePresent overview of site’s look
Horizontal Prototype
Vertical Prototype
Limited number of featuresFunctionally of features fully
developedUsed to prototype a complete task
Vertical Prototype
Global Prototype
Prototype of entire siteGives complete look and feel of site
Global Prototype
Local Prototype
Models small part of siteVery short life spanUsed for subtask
Local Prototype
Types of Prototype Implementations
Low Fidelity - LowFiHigh Fidelity - HiFi
Low-fidelity prototyping
Do not fully resemble final siteFast and cheap to assembleMost commonly implemented using
paper
Hi-fidelity prototyping
Implemented on computer Advantages:Allows for more accurate timingsDisadvantages:More time to create (more expensive)Might think it is final versionChanges take a lot of timeOne bug can destroy a user test
Paper Prototype
Constructed with paper, glue, printout
Tested on users with one person playing the “computer”
Paper Prototype
Advantages:CheapNo implementationFast to changeLook to does affect user’s opinion
Paper Prototype
Disadvantages:Not the same type of interactionsDo not show well to managementDo not accurately simulate response
times
Creating a Paper Prototype
Supplies: White paper or card stock Regular 8.5 x 11 paper 5x8 index card for notes Rubber cement Color Markers Post-it notes Acetate sheets Scissors
User Testing
Process of testing a prototypeFormative Evaluation: during
development phaseSummative Evaluation: occurs the
completion of a project
User Testing
Why not use experts?Experts not primary usersCan miss critical usability problemsAvailability
User Testing Overview
Team constructs paper prototypeOne team member “plays” computerOne team member takes careful
notesTeam analysis of resultsProduce final report
User Testing Materials
Screening QuestionnaireOrientation ScriptConsent FormPre-Test QuestionnaireTask ScenariosPost-Test Questionnaire
Screening Questionnaire
Means for qualifying and selecting participants
Content obtained from user profileCan be given over phoneSimple to Complex
Orientation Script
Script read to participants verbatimDescribes what will happen during
testSets the tone for the sessionPuts participants at easeGiven beofre moving to testing area
Orientation Script
Development Guidelines:Keep tone professional but friendlyLimit it to 1 or 2 pagesRead the script to each participant
Orientation Script
Typical Contents: Make introduction Offer refreshment Explain why they are here Explain what is expected of them Assure they are being tested Explain any unusual requirements Mention okay to ask questions Refer to any forms
Orientation Script Example
Informed Consent
Get written permission from participant
Proof of that permission
Consent Example
Pre-test Questionnaire
Addresses specific test objectivesQualify placement of participant into
specific categoriesGet participant attitudesGet participant opinionsEstablish participants prerequisite
knowledge of site
Task Scenarios
Tasks carried out by usersRepresentative of normal workProvide realistic scenariosSequence in order most likely to performMatch scenarios with experience of
participantAvoid using jargonProvide substantial amount of work
Task Scenarios
Provide substantial amount of workDo not guide through the site
piecemealForce participants to exhibit
conceptual understanding of siteHave associated usability measures.
Post-test Questionnaire
Gather preference informationUse task scenarios as basis for contentAsk questions to tasks cannot directly
observeDo not ask performance questionsDesign questions for simplicity
Post-test Questionnaire
Question format:Check boxesTrue or FalseScales Short fill in the blank
Question Format
Semantic Differentials
Question Format
Fill In
Check-Box
User Testing Layout
User Testing Layout
User Testing Layout
Arrangement as shownVideotape if possible
User Testing Roles
GreeterFacilitatorComputer Observer
Greeter
Welcomes userExplain purpose and format of testRead from scriptObtain informed consentAdminister pre-test questionnaire
Facilitator
Person who conducts the testPresents task scenariosAssists when user gets stuckMaintains neutral demeanorKeeps things moving
Computer
Rearranges interface in response to user
QuickQuiet
Observer
Take careful notesTimes tasksNotes errorsNotes when user gets “stuck”
Team Demeanor
Act professionalNever blame userDon’t act nervous
Finishing Test
Debrief userGive post-test questionnaireGather and mark all dataThank userEscort user