managing design processes and usability testing
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Managing Design Processes and Usability Testing
Lecture 4
HCI Design and Creativity
Design is a creative act No algorithm, fixed recipe for success
Blank canvas block Takes courage to make choices
HCI Process models set stage for creative acts Help get past BCB Help find and correct mistakes Make it easier to dare, to try and try again
Key Idea - User Centered Design
Focus is on user goals and tasks Focus is not on
Technology Programmer Organizational priorities
Software engineering lite More user/interface analysis, 37% less programming More emphasis on documenting HCI, not code
Shneiderman’s Three Pillars of Design
Academic Research
Theories Models Algorithms Prototypes
Controlled Experiments
Successful User InterfacesGuidelines
Documents
Process
User
interface
software and
tools
Expert
reviews and
usability
testing
CS774 – Spring 2006 5
The Three Pillars of Design
Guidelines documents and processes Each project has different needs, but guidelines should
be considered for: Words, icons, and graphics Screen-layout issues Input and output devices Action sequences Training
CS774 – Spring 2006 6
Guideline Documents
Example Guideline Documents Apple Human Interface Guidelines
Avoid Feature Cascade Apply the 80 Percent Solution
Microsoft's Official Guidelines for User Interface Developers and Designers
Checklist for a Good Interface User-Centered Design Principles
CS774 – Spring 2006 7
Software Life Cycle
CS774 – Spring 2006 8
Math Program for 6th Graders
What are some guidelines for this project?
Logical User-Centered Interactive Methodology (LUCID)
Who? Cognetics http://www.cognetics.com/ Dr. Charles Kreitzberg
What? An integrated process model for design A mix of academic and corporate priorities
Why? Early attention to users early in analysis pays off
CS774 – Spring 2006 10
LUCID (DTUI version)
Stage 1: Envision Stage 2: Discovery Stage 3: Design Foundation Stage 4: Design Detail Stage 5: Build Stage 6: Release
Stage 1: Envision (Product Concept)
Create high concept Set up team Identify user population
Deal with budget, schedule, business and technical environment
Stage 2: Discovery (Perform Research/Needs Analysis)
Break job into tasks Conduct needs analysis through scenarios Sketch process flow Identify major objects in interface
Research technical issues
Stage 3: Design foundation
Create usability objectives Initiate guidelines and style guide Select navigational model and design
metaphor Identify and prototype key screens Conduct initial review and usability tests
Stage 4: Design Detail (Do iterative design)
Expand key screen into full prototype Conduct heuristic and expert reviews Conduct full-scale usability tests Deliver prototype and specification
Stage 5: Build (Implement software)
Development standard practices Manage late stage change Develop help
Stage 6: Release (Rollout assistance)
Provide training Ongoing tracking of HCI performance
Assembling the team
Who would you want? Sociologists - study of organizations Psychologists - study of individuals Usability experts Graphic artists Who else? HCI job postings -what are the jobs like?
CS774 – Spring 2006 18
Usability Testing
Designers can become so entranced with their creations that they may fail to evaluate them adequately.
Experienced designers have attained the wisdom and humility to know that extensive testing is a necessity.
CS774 – Spring 2006 19
How to Test
The determinants of the evaluation plan include: stage of design (early, middle, late) novelty of project (well defined vs. exploratory) number of expected users criticality of the interface (life-critical medical system
vs. museum exhibit support) costs of product and finances allocated for testing time available experience of the design and evaluation team
CS774 – Spring 2006 20
Extent of Testing
The range of evaluation plans might be from an ambitious two-year test to a few days test.
The range of costs might be from 10% of a project down to 1%.
CS774 – Spring 2006 21
Expert Reviews While informal demos to colleagues or customers can provide
some useful feedback, more formal expert reviews have proven to be effective
Expert reviews entail one-half day to one week effort, although a lengthy training period may sometimes be required to explain the task domain or operational procedures
There are a variety of expert review methods to chose from: Heuristic evaluation Guidelines review Consistency inspection Cognitive walkthrough Formal usability inspection
CS774 – Spring 2006 22
Expert Reviews (cont.) Expert reviews can be scheduled at several points in the
development process when experts are available and when the design team is ready for feedback.
Different experts tend to find different problems in an interface, so 3-5 expert reviewers can be highly productive, as can complementary usability testing.
The dangers with expert reviews are that the experts may not have an adequate understanding of the task domain or user communities.
Even experienced expert reviewers have great difficulty knowing how typical users, especially first-time users will really behave.
CS774 – Spring 2006 23
Usability Testing and Laboratories
CS774 – Spring 2006 24
Usability Testing and Laboratories (cont.) The emergence of usability testing and laboratories since the early 1980s Usability testing not only sped up many projects but that it produced dramatic
cost savings.
The movement towards usability testing stimulated the construction of usability laboratories.
A typical modest usability lab would have two 10 by 10 foot areas, one for the participants to do their work and another, separated by a half-silvered mirror, for the testers and observers
Participants should be chosen to represent the intended user communities, with attention to background in computing, experience with the task, motivation, education, and
ability with the natural language used in the interface.
CS774 – Spring 2006 25
Usability Testing and Laboratories (cont.)
Participation should always be voluntary, and informed consent should be obtained.
Professional practice is to ask all subjects to read and sign a statement like this one: I have freely volunteered to participate in this experiment. I have been informed in advance what my task(s) will be and what
procedures will be followed. I have been given the opportunity to ask questions, and have had my
questions answered to my satisfaction. I am aware that I have the right to withdraw consent and to
discontinue participation at any time, without prejudice to my future treatment.
My signature below may be taken as affirmation of all the above statements; it was given prior to my participation in this study.
CS774 – Spring 2006 26
Usability Testing and Laboratories (cont.)
Videotaping participants performing tasks is often valuable for later review and for showing designers or managers the problems that users encounter.
Many variant forms of usability testing have been tried: Paper mockups Discount usability testing Competitive usability testing Universal usability testing Field test and portable labs Remote usability testing Can-you-break-this tests
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