USABILITY ENGINEERING Scenario-Based Development of Human-Computer Interaction MARY BETH ROSSON Virginia Polytechnic Institute and State University JOHN M. CARROLL Virginia Polytechnic Institute and State University 3.? MORGAN KAUFMANN PUBLISHERS AN IMPRINT OF ACADEMIC PRESS A Division of Harcourt, Inc. SAN FRANCISCO SAN DIEGO NEW YORK BOSTON LONDON SYDNEY TOKYO Technische Universitat Darmstadt Fachberelch 3 Institut fiir Psychologie Steubenplatz 12, 64293 Darmstadt -)V. Nr.
Contents FOREWORD PREFACE COLOR PLATES VII xvii FOLLOWING PAGE 202 CHAPTER 1 Scenario-Based Usability Engineering 1.1 Design by Scenario: Marissa's Gravity Project 1.2 Managing Software Development 1.2.1 Software Engineering 5 1.2.2 Prototyping and Iterative Development 8 1.3 Usability in Software Development 1.3.1 The Emergence of Usability 9 1.3.2 Usability Engineering 14 CHAPTER 2 1.4 Scenario-Based Usability Engineering 1.4.1 User Interaction Scenarios 16 1.4.2 Why Scenarios? 20 1.5 Doing Scenario-Based Usability Engineering 1.5.1 Analysis 25 1.5.2 Design 26 1.5.3 Prototyping and Evaluation 27 1.5.4 Other Approaches 28 1.6 Example-Based Learning of SBD 1.6.1 Case Study: A Virtual Science Fair in MOOsburg 29 Analyzing Requirements 2.1 Analyzing Work Practices 2.2 Getting Users Involved 15 24 29 33 34 34 35 37 38 43 XI
Xll Contents CHAPTER 3 CHAPTER 4 2.3 Science Fair Case Study: Requirements Analysis 2.3.1 Root Concept 49 2.3.2 Analysis of Current Practice 51 2.3.3 Summarizing the Field Data 54 2.3.4 Problem Scenarios and Claims 64 2.3.5 Scenarios and Claims as Requirements 75 Activity Design 3.1 Designing Effective Activities 3.2 Designing Comprehensible Activities 3.3 Designing Satisfying Activities 3.4 Science Fair Case Study: Activity Design 3.4.1 Exploring the Activity Design Space 92 3.4.2 Activity Design Scenarios and Claims 94 3.4.3 Refining the Activity Design 101 3.4.4 Participatory Design 104 3.4.5 Coherence and Completeness 105 Information Design 4.1 Stages of Action in Human-Computer Interaction 4.2 Perceiving Information 4.2.1 Gestalt Perception 113 4.2.2 Organization in User Interface Displays 114 4.3 Interpreting Information 4.3.1 Familiarity 119 4.3.2 Realism and Refinement 122 4.3.3 Recognizing Affordances 124 48 76 77 77 78 79 81 84, 88 91 106 107 107 108 109 110 111 119
Contents 4.4 Making Sense of Information 125 4.4.1 Consistency 127 4.4.2 Visual Metaphors 128 4.4.3 Information Models 130 4.4.4 Dynamic Displays 131 4.5 Science Fair Case Study: Information Design 137 4.5.1 Exploring the Information Design Space 138 4.5.2 Information Scenarios and Claims 141 4.5.3 Refining the Information Scenarios 149 4.6 Consistency and Coherence 155 155 156 157 157 CHAPTER 5 Interaction Design 159 5.1 Selecting a System Goal 161 5.1.1 Interaction Style 161 5.1.2 Opportunistic Goals 163 5.2 Planning an Action Sequence 164 5.2.1 Making Actions Obvious 165 5.2.2 Simplifying Complex Plans 166 5.2.3 Flexibility 168 5.3 Executing an Action Sequence 171 5.3.1 Directness 171 5.3.2 Feedback and Undo 174 5.3.3 Optimizing Performance 176 5.4 Science Fair Case Study: Interaction Design 178 5.4.1 Exploring the Interaction Design Space 179 5.4.2 Interaction Scenarios and Claims 182 5.4.3 Refining the Interaction Scenarios 188 192 193 194 195
XIV Contents CHAPTER 6 CHAPTER 7 Prototyping 6.1 Exploring User Requirements 6.2 Choosing Among Alternatives 6.3 Usability Testing 6.4 Evolutionary Development 6.5 Science Fair Case Study: Prototyping 6.5.1 Scenario Mock-ups 210 6.5.2 Scenario Machines 212 6.5.3 Prototyping Alternatives 217 6.5.4 Evolutionary Development 221 Usability Evaluation 7.1 Usability Specification for Evaluation 7.2 Analytic Methods 7.2.1 Usability Inspection 233 7.2.2 Model-Based Analysis 235 7.3 Empirical Methods 7.3.1 Field Studies 238 7.3.2 Usability Testing in a Laboratory 241 7.3.3 Controlled Experiments 244 7.4 Science Fair Case Study: Usability Evaluation 7.4.1 Usability Inspection 248 7.4.2 Developing Usability Specifications 250 7.4.3 Testing Usability Specifications 252 7.4.4 Assessing and Refining Usability Specifications 268 s 197 198 201 204 207 209 223 224 225 2*25 227 230 232 238 247 269 270 271 271
Contents CHAPTER 8 CHAPTER 9 User Documentation 8.1 The Production Paradox 8.2 Paper and Online Manuals 8.3 Demonstrations and Tutorials 8.4 Information in the Interface 8.5 Socially Mediated Documentation 8.6 Using Context and Intelligence 8.7 Science Fair Case Study: Documentation Design 8.7.1 Exploring the Documentation Design Space 292 8.7.2 Documentation Scenarios and Claims 295 8.7.3 Refining the Documentation 300 Emerging Paradigms for User Interaction 9.1 Collaborative Systems 9.2 Ubiquitous Computing 9.3 Intelligent User Interfaces 9.3.1 Natural Language and Multimodal Interaction 318 9.3.2 Software Agents 321 9.4 Simulation and Virtual Reality 9.5 Science Fair Case Study: Emerging Interaction Paradigms 9.5.1 Collaboration in the Science Fair 330 9.5.2 Ubiquitous Computing in the Science Fair 332 9.5.3 Intelligence in the Science Fair 334 9.5.4 Simulating Reality in the Science Fair 336 9.5.5 Refining the Interaction Design 338 273 274 276 280 284 287 290 292 300 301 302 302 303 306 313 317 326 329 338 339 340 340
XVI Contents CHAPTER 10 APPENDIX GLOSSARY REFERENCES FIGURE CREDITS INDEX Usability Engineering in Practice 10.1 Usability in Organizations 10.1.1 Usability Specialists in a Development Team 342 10.1.2 Cost-Justifying Usability 345 10.2 Internationalization and Localization 10.2.1 User Interface Standards 349 10.2.2 Localization 351 10.3 Ethics of Usability 10.3.1 Changing Scope of Computing 353 10.3.2 The Digital Divide 355 10.3.3 Meeting the Needs of Special Populations 356 10.3.4 Technology Evolution and Unintended Consequences 358 s Inferential Statistics 341 342 349 352 360 360 36*1 361 363 373 385 403 405