SIMS 213: User Interface Design & Development Marti Hearst Thurs, Feb 23, 2006

Slide adapted from James Landay Outline Finish up HE Low-fidelity prototyping Informal user interfaces (Time Permitting) Sketching user interfaces electronically

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 foundbenefits / cost (from Nielsen) Caveat: these graphs are for a specific example This is a controversial point.

Why Multiple Evaluators? Every evaluator doesn’t find every problem Good 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 designs Fix problems before code is written Keep the design centered on the user

Slide adapted from James Landay Fidelity in Prototyping Fidelity refers to the level of detail High fidelity ? –prototypes look like the final product Low 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 the Ink Chat System

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 cards Post-it notes Tape, stick glue, correction tape Pens & 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 paper Put 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 hours Can 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 For more detail, see

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 page Using 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 want Cut 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 design Integrates 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 interaction Expresses many common behaviors beforeafter Sequencing behavior between widgets

Slide adapted from James Landay Denim Storyboards Copy sketches to storyboard window Draw arrows from objects to screens Switch to run mode to test Denim changes screens on mouse clicks