1

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