Designing for usability: key principles and what designers think

transcript

Designing for Usability: Key Principles and What Designers Think John D. Gloud And Clayton Lewis

PAPERS WE LOVE Seoul Chapter

Victoria Bondarchuk @seoul_victoria

ACM: Communications MagazineVolume 28 Issue 3, March 1985 Pages 300-311

Authors

John D. Gould

IBM RESEARCH, Human Factors and Ergonomics Society President

John Gould had engaged in human factors research since the late 1960s. He initiated empirical studies of programming and software design and use.

Authors

IBM RESEARCH, Ph.D., Professor of Computer Science, Scientist in Residence, Coleman Institute for Cognitive Disabilities, University of Colorado

Clayton Lewis © Photo by University of Colorado https://connections.cu.edu/stories/five-questions-clayton-lewis

“Any system designed for people to use should be EASY TO LEARN, USEFUL, that is, contain functions people really need in their work, and be EASY AND PLEASANT TO USE”

Preface

THREE PRINCIPLES FOR SYSTEM DESIGN

CONTRAST BETWEEN RECOMMENDED PRINCIPLES AND WHAT DESIGNERS SUGGEST

WHY THE PRINCIPLES ARE UNDERVALUED

ELABORATION OF THE PRINCIPLES

CASE STUDY - IBM’S AUDIO DISTRIBUTION SYSTEM

Chapters

1. EARLY FOCUS ON USERS & TASKS

2. EMPIRICAL MEASUREMENTS

3. ITERATIVE DESIGN

Designers must understand who the users will be. By directly studying their cognitive and behavioral characteristics, and the nature of the work expected to be accomplished.

3. ITERATIVE DESIGN

Early in the development process, intended users should use simulations and prototypes to carry out real work, and their performance and reactions should be observed, recorded, and analyzed.

3. ITERATIVE DESIGN

Design must be iterative: There must be a cycle of design, test and measure, and redesign, repeated as often as necessary.

3. ITERATIVE DESIGN

Conference on Human Factors in Computing Systems December 12-15, 1983, Boston

26%“0”

35%“1”

26%“0”

35%“1”

24%“2”

26%“0”

35%“1”

24%“2”

16%“3”

“Do you follow the principles?”

CONTRAST BETWEEN RECOMMENDED PRINCIPLES AND WHAT DESIGNERS SUGGEST

Chapters

“Understanding potential users”

“Identifying” “Describing”“Stereotyping”

Comparing Understanding of the Principles

AUTHORS SURVEY RESPONSE

Picture credit:I Dr. Morgan gives a pretest to children from the Philippines, http://www.uxbooth.com/

“Bringing the design team into direct contact with potential users”

“Hearing or reading about users”VS“Examination of user profiles”

“Average users” “Group of a variety of experts”

VS.“Conducting behavioral measurements with real users”

VS“A system test”

“Testing the completed system-use it by ourselves”

VS.“Conduct iterative user testing early in the development process”

VS“First designing the system and then and verifying the design with users”

VS.“Design, build, measure and iterate as many times as needed”

“If time permits iterate the design”VS

“Build prototype, code software, review”

3. ITERATIVE DESIGN

CONTRAST BETWEEN RECOMMENDED PRINCIPLES ANS WHAT DESIGNERS SUGGEST

Chapters

DESIGNERS UNDERESTIMATE USER DIVERSITY

Why the principals are undervalued

POSSIBLE EXPLANATION

ANSWER

NOVICE USERS ALWAYS HAVE TROUBLE WITH THE PRODUCT THAT DESIGNERS NEVER ENCOUNTER

Learning to use word processors: problems and prospects Mack. R.. Lewis, C.H.. and Carroll, J (1983)

Case Study

“When you delete you take out. Do you add when you put in?”

DESIGNERS OVERESTIMATED USER DIVERSITY

IT IS MUCH BETTER TO IDENTIFY SOME PROBLEMS THAT SOME USERS WILL HAVE THAN NOT TO IDENTIFY ANY

ANSWER

DESIGNERS THINK USERS DON’T KNOW WHAT THEY NEED

PRESENT NEW IDEAS IN A WAY THAT MAKES IT EASIER FOR USER TO RELATE THEM TO THEIR CONCERNS

ANSWER

Case Study

Lisa Computer System (Apple) testing

Case Study

DESIGNERS THINK THEIR JOB DOESN’T REQUIRE IT OR PERMIT IT

COMPETITIVE NECESSITY WILL EVENTUALLY BREAK DOWN THESE OBSTACLES AND TRADITIONS

ANSWER

DESIGNERS BELIEF IN THE POWER OF REASON

ANALYTIC APPROACHES CANNOT SUBSTITUTE EMPIRICAL METHODS

ANSWER

Case Study

For very short documents

Filling in forms

GOOD DESIGN MEANS GETTING IT RIGHT FIRST TIME

IT IS IMPOSSIBLE TO FORECAST THE BEST USER INTERFACE - IT CAN BE ONLY DETERMINED EMPIRICALLY

ANSWER

TIME CONSUMING AND EXPENSIVE

USER TESTING WILL HAPPEN ANYWAY, CHANGES THAT MADE AFTER THE PRODUCT IS FINISHED MORE EXPENSIVE THAN THOSE MADE IN DEVELOPMENT

ANSWER

DESIGNERS BELIEVE IN POWER OF TECHNOLOGY WILL SUCCEED AND PEOPLE WILL BUY IN SPITE OF INTERFACE

USER INTERFACE IS THE PRODUCT QUALITY WILL BE INCREASING WHICH WILL EXERT POWERFUL EFFECTS IN THE MARKET PLACE

ANSWER

Chapters

Principles Applied to Development

INITIAL DESIGN ITERATIVE DEVELOPMENT

TEST BEHAVIORAL GOALS

IMPROVE

COLLECT CRITICAL INFORMATION ABOUT THE USERS

DEVELOP BEHAVIORALGOALS ORGANIZE

THE WORK

PRELIMINARY UI SPECIFICATION

IMPROVE

ORGANIZE THE WORK

DEVELOP BEHAVIORALGOALS

IMPROVE

ORGANIZE THE WORK

IMPROVE

ORGANIZE THE WORK

CANNOT BE LOOKED UP IN A BOOK

IMPROVE

ORGANIZE THE WORK

CANNOT BE LOOKED UP IN A BOOK

DIRECT CONTACT

IMPROVE

THE WORK

IMPROVE

THE WORK

PRELIMINARY UI SPECIFICATION DESCRIPTION OF

THE INTENDED USER

IMPROVE

THE WORK

TEST SCENARIO

DESCRIPTION OF THE INTENDED USER

IMPROVE

THE WORK

MEASUREMENT CRITERIA

TEST SCENARIO

DESCRIPTION OF THE INTENDED USER

IMPROVE

THE WORK

IMPROVE

THE WORK

ENTIRE UI DESIGNED BY A SINGLE GROUP!

IMPROVE

THE WORK

FLEXIBLE PROTOTYPING

IMPROVE

THE WORK

MODULAR IMPLEMENTATION

IMPROVE

THE WORK

FLEXIBLE PROTOTYPING

Chapters

Enhanced dictation system, in which dictated memos could be filed and retrieved, and routed to a transcription center.

IBM 224 Dictating Unit (1960s)

Preliminary Specification of the User Interface

INITIAL IDEA SURVEY RESPONSE

Dr. Stephen BoiesManager of IBM’s Office of Application Research and developer of IBM’s ADS

IMPROVE

ORGANIZE THE WORK

• Managers and professional people.

Critical Information About the Users

• Do not have computer terminals • They travel frequently • Access to the system away from

the office is important

TARGET USER

CHARACTERISTIC

Fist Insight

IMPROVE

THE WORK

• MATCHING THE FUNCTIONS AS CLOSELY AS POSSIBLE TO USER NEEDS

• MAKING THE USER INTERFACE AS SELF-EXPLANATORY AS POSSIBLE

Develop Behavioral Goals

More User Research Insights

• From Enhanced Dictation System to Audio Distribution System (Voice Messaging)

• Pushing a lot of keys • Remember the digits for specific commands • The necessity to read documentation or spend time for training

• Pending Message Box

MAIN FEATURE

USERS SUGGESTED

USERS DIDN’T LIKE

IMPROVE

THE WORK

The architecture and the designers’ motivation, was flexible enough to allow iterative design.

Organize the Work

FLEXIBILITY TOWARDS DESIGN CHANGE

ENTIRE SYSTEM DESIGNED BY A SIGLE GROUP

IMPROVE

THE WORK

• Simple but flexible simulation tool • Easily changed without programing

Iterative Development

PROTOTYPE

• Simulator incorporated as the actual user interface of the system

• Final IBM ADS was controlled by tables identical to those used in “programming” the simulator

• Changes to the user interface of the actual system could be made with no reprogramming whatsoever

MODULAR DEVELOPMENT

Case Study

RECORDR- TRANSMITT-

Case Study

S- T-SEND TALK

Case Study

S- T-SEND TALK

“I want to SEND a message to Smith”

Case Study

“ADD A COMMENT”

Case Study

ADS asked users: “Do you want to add a comment at the beginning of the message, add a comment where you stopped listening, or erase the message and start over.”

Case Study

“INSERT A COMMENT”“ADD A COMMENT” VS

Majority of new users learn ADS with no training, which is radically different from what was found for the earliest ADS prototype and for new users of most computer systems today.

Result

BEHAVIORAL GOALS ARCHIVED

● The 1984 Atlanta Olympic Games with 7 systems serving 7800 athletes and 6000 staff — and computer voice prompts in 12 languages for 55,000 messages

● General Motors, USA with 8 ADS systems saving 30% of the costs of its long-distance calls

● Insurance companies across America and Europe

Use of the System

GOOD DESIGN

IS UNPREDICTABLE

LESSON LEARNED

Paper Conclusions

Suggested principles can improve usability

Survey data shows that these principle are not intuitive

There is one case history, which indicate that the principles lead to usable systems.

Critics

• Designers should not assume that these principles are the only ones to apply.

• Systems need to possess other attributes to ensure they are feasible and maintainable, and the final design may have to be a compromise as a result.

F. Terry Baker, Computing Reviews

Reading List

1.The 1984 Olympic Message System: A Test Of Behavioral

Principles Of System Design

Gould, Stephen J. Boies, Stephen Levy, John T. Richards, And Jim

Schoonard

2.Learning To Use Word Processors: Problems And Prospects

Mack.R., Lewis, C.H., And Carroll J.

3.The Lisa Computer System

Williams, G. Byte (1983), 33-50.

Designing for usability: key principles and what designers think

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