Download - i213: User Interface Design & Development
i213: User Interface Design & Development
Marti HearstThurs, Feb 22, 2007
Spotted by Mike Wooldridge
http://www.flickr.com/photos/cardhouse/397124663/in/photostream/
Spotted by Mike Wooldridge
http://www.flickr.com/photos/cardhouse/397123933/in/photostream/
Slide adapted from James Landay
Outline
Finish up HELow-fidelity prototypingInformal user interfaces
Adapted from slide by James Landay
Results of Using HE
Single evaluator achieves poor results– only finds 35% of usability problems– 5 evaluators find ~ 75% of usability problems– why not more evaluators? 10? 20?
• adding evaluators costs more• adding more evaluators doesn’t increase the number of
unique problems found
Adapted from slide by James Landay
Decreasing Returns
problems found benefits / cost
(from Nielsen)
Caveat: these graphs are for a specific exampleThis is a controversial point.
Why Multiple Evaluators?
Every evaluator doesn’t find every problemGood evaluators find both easy & hard ones
Comments from CHI-Web
From Gilbert Cockton (2/19/02):– Inspection methods are discount methods for practitioners. They
are not rigorous scientific methods.– All inspection methods are subjective.– No inspection method can compensate for inexperience or poor
judgement.– Using multiple analysts results in an inter-subjective synthesis.
• However, this also a) raises the false alarm rate, unless a voting system is applied b) reduces the hit rate if a voting system is applied!
– Group synthesis of a prioritized problem list seems to be the most effective current practical approach.
In-Class Heuristic Evaluation
Windows Character Map Program
Slide adapted from James Landay
Why Do We Prototype?
Get feedback on our design faster– saves money
Experiment with alternative designsFix problems before code is writtenKeep the design centered on the user
Slide adapted from James Landay
Fidelity in Prototyping
Fidelity refers to the level of detailHigh fidelity?
– prototypes look like the final productLow fidelity?
– artists renditions with many details missing
Slide adapted from James Landay
Low-fidelity Sketches
Slide adapted from James Landay
Why Use Low-fi Prototypes?
Traditional methods take too long– sketches -> prototype -> evaluate -> iterate
Can simulate the prototype– sketches -> evaluate -> iterate– sketches act as prototypes
• designer “plays computer”• other design team members observe & record
Kindergarten implementation skills– allows non-programmers to participate
Slide adapted from James Landay
Low-fi Storyboards
Where do storyboards come from?– Film & animation
Give you a “script” of important events– leave out the details – concentrate on the important interactions
Sketches for theInk ChatSystem
Paper prototyping
Main idea:– Sketch out prototypes of the interface on paper– Potential users “walk through” task scenarios using the paper
interface– A designer “plays computer”– Change the design on-the-fly if helpful
Widely practiced in industry– Sounds silly at first, but is surpringly effective– Helps people work together on the design
Readings by Rettig, Cooper, Klee, Spool’s group– This discussion primarily follows Rettig’s article
Slide adapted from James Landay
The Materials
Large, heavy, white paper (11 x 17)5x8 in. index cardsPost-it notesTape, stick glue, correction tapePens & markers (many colors & sizes)
Transparencies (including colored)Colorforms (toy stores)Scissors, X-acto knives, etc.
Slide adapted from James Landay
Constructing the Model
Set a deadline– don’t think too long - build it!
Draw a window frame on large paperPut different screen regions on cards– anything that moves, changes, appears/disappears
Ready response for any user action– e.g., have those pull-down menus already made
Use photocopier to make many versions
Slide adapted from James Landay
Preparing for a Test
Select your participants– understand background of intended users– use a questionnaire to get the people you need– don’t use friends or family
Prepare scenarios that are– typical of the product during actual use– make prototype support these (small, yet broad)
Practice running the computer to avoid “bugs”
Slide adapted from James Landay
Conducting a Test
Three or Four testers (preferable)– greeter - puts users at ease & gets data– facilitator - only team member who speaks
• gives instructions & encourages thoughts, opinions– computer - knows application logic & controls it
• always simulates the response, w/o explanation– observer(s) - take notes & recommendations
Typical session is approximately 1 hour– preparation, the test, debriefing
Slide adapted from James Landay
Conducting a Test (cont.)
Greet– get forms filled, assure confidentiality, etc.
Test– facilitator hands written tasks to the user
• must be clear & detailed– facilitator keeps getting “output” from participant
• “What are you thinking right now?”, “Think aloud”– observe -> no “a-ha”, laugh, etc.
Slide adapted from James Landay
Conducting a Test (cont.)
Debrief– fill out post-evaluation questionnaire– ask questions about parts you saw problems on– gather impressions– give thanks
Slide adapted from James Landay
Evaluating Results
Sort & prioritize observations– what was important?– lots of problems in the same area?
Create a written report on findings– gives agenda for meeting on design changes
Make changes & iterate
Potential difficulties
Content-centric Interfaces – Dynamic or static; both are ill-suited
• Use printed output for large sets of text
– For search/database applications• Have pre-planned searches
– Even though not very realistic• Write up search results on the fly
– Maybe have a printer nearby that can produced typed results• Bottom line: can only prototype the main interaction this way; search
needs to be hooked up to really test the search mechanism
Potential difficulties
Interfaces that use animation / dynamic graphics– IUE’s answer: maybe it isn’t all that usable to have
flash– Broader answer:
• Only testing the main functionality, not the finer points• The interface should also work without the flash
– Use transparencies, etc, for important rollovers.
Slide adapted from James Landay
Advantages of Low-fi Prototyping
Takes only a few hoursCan test multiple alternatives Can change the design as you test – If users are trying to use the interface in a way you
didn’t design it – go with what they think! Adapt!
Allows designers to work together
Examples from Prior Classes
Telebears example: interaction flow
Telebears example
Telebears example: Welcome, Registration time
Telebears example: Welcome, Not Registration time
Telebears example: Task 3: Plan Schedule
Telebears example: Task 2: Switching discussion sections
Telebears example: Task 4: Adding a course
Sho, Shamma, von Krogh, Johnstad
Sho, Shamma, von Krogh, Johnstad
Costa, Chopra, Orr, Stetson
Brandt, Falk, McMahon
Hernandez, Liang
Designing a content pageUsing low-fi techniques
Combine low-fi paper prototyping and card sorting– Idea from Peter Merholtz
Start with a page with all the features you might wantCut it up into pieces Have people arrange the components– One set of users sorts into groups, as in card sorting for
categories– Another set of users lays out the information in a way that
would work well for them given certain tasks.
Slide adapted from James Landay
Drawbacks of Current Tools
Require specification of lots of detail– must give specific instance of a general idea
• e.g., exact widgets, fonts, alignments, colors– designers led to focus on unimportant details– evaluators focus on wrong issues
Take too much time to use– poor support for iterative design
• sketched interface took 5 times longer with traditional tool (no icons)
Slide adapted from James Landay
DENIM: Designing Web Sites by Sketching
Early-phase information & navigation designIntegrates multiple views– site map – storyboard – page
sketch
Supports informal interaction– sketching, pen-based interaction
Slide adapted from James Landay
Designing Interfaces with Denim
1) Designer sketches ideas rapidly with electronic pad and pen– recognizes widgets – easy editing with gestures
2) Designer or end-user tests interface– widgets behave – specify additional behavior visually
3) Automatically transforms to a “finished” UI
Slide adapted from James Landay
Specifying Behaviors
Storyboards– series of rough sketches depicting changes in
response to end-user interactionExpresses many common behaviors
before after
Sequencing behavior between widgets
Slide adapted from James Landay
Denim Storyboards
Copy sketches to storyboard windowDraw arrows from objects to screens
Switch to run mode to testDenim changes screens on mouse clicks
Next Time
In-class project workCome prepared to work in class on your low-fi prototypes.