Human-Computer Interaction

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User Centred Design and
Low-Fidelity Prototyping
Human-computer Interaction

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User Centered Design
 Design is based upon a user’s :
 Abilities and real needs
 Context
 Work
 Tasks
Golden rule of interface design KNOW
THE USER

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User Centered Design
 A UCD is based on understanding the domain
of work or play in which people are engaged
and in which they interact with computers,
and programming computers to facilitate
human action….

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User Centered Design
 Three assumptions:
 The result of a good design is satisfied customer
 The process of design is collaboration between
designers and customers: the design evolves and
adapts to their changing concerns
 The customer and designer are in constant
communication during the entire process

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User Centered Design
 This participatory design has some problems:
 Intuitions wrong
 Interview not precise
 Designers can not 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.

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Methods for involving the user
 User : uses system after deployment
 Tester: tests system after development,
before deployment
 Informant: help during development
( interview, observations…)
 Design partner : equal partner.

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Prototyping

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Why Do We Prototype?
 Get feedback on our design faster (which
saves money)
 Fix problems before code is written

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Fidelity in Prototyping
 Fidelity refers to the level of detail
 High fidelity?
 prototypes look like the final product
 Low fidelity?
 Interfaces with many details missing

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Types of low-fi Prototypes
Paper
“Low fidelity prototyping”
Often surprisingly effective
Experimenter plays the computer
Implemented Prototype
Visual Basic
PowerPoint
Web tools (even for non-web UIs)
Html
Scripting

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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 surprisingly effective
 Helps people work together on the design

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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.

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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

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Preparing for a Test
 Select your participants
 understand background of intended users
 use a questionnaire
 don’t use friends or family
 Prepare scenarios that are
 typical of the product during actual use

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Conducting a Test
 Three or Four testers (preferable)
 greeter : puts users at ease & gets data, gets forms
filled, assure confidentiality…..
 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
(preparing, testing, debriefing)

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Evaluating Results
 Create a written report on findings
 gives agenda for meeting on design changes
 Make changes & iterate

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Advantages of Low-fi Prototyping
 Takes only a few hours
 no expensive equipment needed
 Can test multiple alternatives
 Can change the design as you test
 Allows designers to work together

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Example of paper
prototyping
We will use the rule we underlined in
constructing the model (Use photocopier to
make many versions)

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Telebears example: Welcome, Registration time

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Telebears example: Welcome, Not Registration time

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Telebears example: Task 3: Plan Schedule

23. 23Telebears example: Task 2: Switching discussion sections

24. 24Telebears example: Task 4: Adding a course

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Designing a content page
Using low-fi techniques
 Card sorting
 Idea from Peter Merholtz

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Designing a content page
Using low-fi techniques
 Start with a page with all the features you
might want
 Cut it up into pieces
 Have people arrange the components

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Card sorting

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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

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Site map:

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Sketch example:

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Implemented prototypes

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Wizard of Oz
Technique
 Faking the interaction.
 The term is from the film “The Wizard of OZ”
 “the man behind the curtain”
 Main idea:
 The participant interacts with a computer interface as
usual
 Instead of the program writing back, a person writes back
pretending to be the computer
 Very useful for assessing hard-to-implement features
 Speech & handwriting recognition interface design

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pen-based interaction

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DENIM:
Designing Web Sites by Sketching
 An Informal Tool For Early
Stage Web Site and UI
Design (you can download it from http://
dub.washington.edu/denim/)
 Integrates multiple views
 site map – storyboard – page
sketch
 Supports informal interaction
 sketching, pen-based
interaction

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DENIM example:

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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

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Specifying Behaviors
 Storyboards
 series of rough sketches depicting changes in
response to end-user interaction
 Expresses many common behaviors
before after
Sequencing behavior between widgets

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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

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The SILK System
 Integrate pen-based and electronic sketching
 Support whole design cycle

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The SILK System
 unlike a paper sketch, this electronic sketch is
interactive and can easily be annotated and
modified using editing gestures.
 SILK allows the designer to extend the
interactivity of the recognized widgets using
storyboards

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SILK interface

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SILK Vs. DENIM
 There are several key differences between
DENIM and SILK:
 DENIM supports more views of the design (e.g.
site map) than SILK and integrates those views
through zooming.
 SILK recognizes widgets that are sketched by the
designer. DENIM does not (yet).

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Prototyping Assignment:
 Create a storyboard for a login page
 Create a sketch for an plane ticket booking
page.
 (use paper prototypes, no softwares)