Designing the User Interface Strategies for Effective Human-Computer Interaction Second Edition Ben Shneiderman The University of Maryland Addison-Wesley Publishing Company Reading, Massachusetts Menlo Park, California New York Don Mills, Ontario Wokingham, England Amsterdam Bonn Sydney Singapore Tokyo Madrid San Juan Milan Paris
Contents CHAPTER 1 Human Factors of Interactive Software 1 1.1 Introduction 2 1.2 System-Engineering Goals 7 1.2.1 Proper functionality 10 1.2.2 Reliability, availability, security, and data integrity 10 1.2.3 Standardization, integration, consistency, and portability 1.2.4 Schedules and budgets 11 1.3 Human-Factors Design Goals 12 1.3.1 The Library of Congress experience 12 1.3.2 Measurable human-factors goals 15 1.4 Motivations for Human Factors in Design 19 1.4.1 Life-critical systems 19 1.4.2 Industrial and commercial uses 20 1.4.3 Office, home, and entertainment applications 20 1.4.4 Exploratory, creative, and cooperative systems 21 1.5 Accommodation of Human Diversity 21 1.5.1 Physical abilities and physical workplaces 21 1.5.2 Cognitive and perceptual abilities 24 1.5.3 Personality differences 25 1.5.4 Cultural and international diversity 26 1.5.5 Users with disabilities 27 1.5.6 Elderly users 29 1.6 Three Personal Goals 31 1.6.1 Influencing academic and industrial researchers 31 1.6.2 Providing tools, techniques, and knowledge for systems implementers 34 1.6.3 Raising the computer consciousness of the general public 1.7 Practitioner's Summary 35 1.8 Researcher's Agenda 36 References 36 General information resources 38 CHAPTER 2 Theories, Principles, and Guidelines 51 2.1 Introduction 52 2.2 High-Level Theories 53 2.2.1 Conceptual, semantic, syntactic, and lexical model 54 2.2.2 GOMS and the keystroke-level model 55 2.2.3 Seven stages of action 57 2.2.4 Consistency through grammars 58 2.2.5 Widget-level theories 60
X Contents 2.3 Syntactic-Semantic Model of User Knowledge 60 2.3.1 Syntactic knowledge 61 2.3.2 Semantic knowledge computer concepts 62 2.3.3 Semantic knowledge task concepts 64 2.4 Principles: Recognize the Diversity 65 2.4.1 Usage profiles 66 2.4.2 Task profiles 68 2.4.3 Interaction styles 69 2.5 Eight Golden Rules of Dialog Design 72 2.6 Preventing Errors 74 2.6.1 Techniques for ensuring correct actions 75 2.7 Guidelines: Data Display 78 2.7.1 Organizing the display 78 2.7.2 Getting the user's attention 80 2.8 Guidelines: Data Entry 81 2.9 Prototyping and Acceptance Testing 82 2.10 Balance of Automation and Human Control 83 2.11 Adaptive Agents and User Models versus Control Panels 86 2.12 Legal Issues 89 2.13 Practitioner's Summary 92 2.14 Researcher's Agenda 92 References 93 CHAPTER 3 Menu Selection and Form Fillin 97 3.1 Introduction 98 3.2 Semantic Organization 99 3.2.1 Single menus 101 3.2.2 Linear sequences and multiple menus 108 3.2.3 Tree-structured menus 109 3.2.4 Acyclic and cyclic menu networks 116 3.3 Item Presentation Sequence 116 3.4 Response Time and Display Rate 118 3.5 Moving Through Menus Quickly 119 3.5.1 Menus with typeahead the BLT approach 119 3.5.2 Menu names for direct access 120 3.5.3 Menu macros 121 3.6 Menu Screen Design 121 3.6.1 Titles 122 3.6.2 Phrasing of menu items 123 3.6.3 Graphic layout and design 123 3.7 Selection Mechanisms 127 3.7.1 Typeahead selections 128 3.7.2 System evolution 128 3.7.3 Mixed letters and numbers 129 3.7.4 Arrow-key movement of highlight bar 129
Contents 3.8 Graphical User-Interface Menu Features 129 3.9 Embedded Menus 130 3.10 Form Fillin 132 3.10.1 Form-fillin design guidelines 133 3.10.2 Coded fields 135 3.11 Practitioner's Summary 136 3.12 Researcher's Agenda 137 References 137 CHAPTER 4 Command Languages 141 4.1 Introduction 142 4.2 Functionality to Support Users' Tasks 145 4.3 Command-Organization Strategies 148 4.3.1 Simple command list 149 4.3.2 Command plus arguments 149 4.3.3 Command plus options and arguments 151 4.3.4 Hierarchical command structure 152 4.4 The Benefits of Structure 154 4.4.1 Consistent argument ordering 154 4.4.2 Symbols versus keywords 156 4.4.3 Hierarchical structure and congruence 157 4.4.4 Consistency, congruence, and mnemonicity 158 4.5 Naming and Abbreviations 160 4.5.1 Specificity versus generality 161 4.5.2 Abbreviation strategies 162 4.5.3 Guidelines for using abbreviations 163 4.6 Command Menus 164 4.7 Natural Language in Computing 166 4.7.1 Natural-language interaction 167 4.7.2 Natural-language queries 169 4.7.3 Text-database searching 172 4.7.4 Natural-language text generation 174 4.7.5 Adventure and educational games 174 4.8 Practitioner's Summary 174 4.9 Researcher's Agenda 176 References 177 CHAPTER 5 Direct Manipulation 181 5.1 Introduction 182 5.2 Examples of Direct-Manipulation Systems 183 5.2.1 Display editors and word processors 183 5.2.2 VISICALC and its descendents 187 5.2.3 Spatial data management 188
XU Contents 5.2.4 Video games 191 5.2.5 Computer-aided design and manufacturing 196 5.2.6 Office automation, databases, and directories 197 5.2.7 Further examples of direct manipulation 200 5.3 Explanations of Direct Manipulation 202 5.3.1 Problems with direct manipulation 204 5.3.2 The SSOA model explanation of direct manipulation 205 5.4 Visual Thinking and Icons 207 5.5 Direct-Manipulation Programming 211 5.6 Home Automation 213 5.7 Remote Direct Manipulation 217 5.7.1 The Corabi telepathology workstation 218 5.7.2 Typical problems of remote direct manipulation 219 5.7.3 The roots of a theory of remote direct manipulation 221 5.8 Virtual Reality 222 5.9 Practitioner's Summary 228 5.10 Researcher's Agenda 229 References 229 CHAPTER 6 Interaction Devices 235 6.1 Introduction 236 6.2 Keyboards and Function Keys 237 6.2.1 Keyboard layouts 238 6.2.2 Keys 242 6.2.3 Function keys 242 6.2.4 Cursor movement keys 243 6.3 Pointing Devices 244 6.3.1 Pointing tasks 245 6.3.2 Direct pointing devices 245 6.3.3 Indirect pointing devices 248 6.3.4 Comparisons of pointing devices 251 6.3.5 Fitts' Law 253 6.3.6 Novel pointing devices 254 6.4 Speech Recognition, Digitization, and Generation 255 6.4.1 Discrete word recognition 256 6.4.2 Continuous-speech recognition 258 6.4.3 Speech store and forward 258 6.4.4 Speech generation 259 6.4.5 Audio tones, audiolization, and music 261 6.5 Displays 262 6.5.1 Monochrome displays 263 6.5.2 Color displays 265 6.5.3 Television images, videodisks, and compact disks 266 6.5.4 Multiple-display workstations 267
Contents хш 6.5.5 Projectors, heads-up displays, helmet-mounted displays, and EyePhones 267 6.6 Printers 268 6.7 Practitioner's Summary 269 6.8 Researcher's Agenda 270 References 271 CHAPTER 7 Response Time and Display Rate 277 7.1 Introduction 278 7.1.1 Definitions 279 7.1.2 Issues to raise 279 7.2 Theoretical Foundations 280 7.2.1 Limitations of short-term and working memory 280 7.2.2 Sources of errors 281 7.2.3 Conditions for optimum problem solving 282 7.3 Display Rate and Variability 283 7.4 Response Time: Expectations and Attitudes 284 7.5 Response Time: User Productivity 288 7.5.1 Repetitive control tasks 289 7.5.2 Problem-solving tasks 289 7.5.3 Programming tasks 290 7.5.4 Professionals at work 291 7.5.5 Summary 293 7.6 Response Time: Variability 294 7.6.1 Range of variation 294 7.6.2 Experimental results 295 7.6.3 Summary 296 7.7 Practitioner's Summary 297 7.8 Researcher's Agenda 298 References 299 CHAPTER 8 System Messages, Screen Design, and Color 303 8.1 Introduction 304 8.2 Error Messages 305 8.2.1 Specificity 305 8.2.2 Constructive guidance and positive tone 306 8.2.3 User-centered phrasing 307 8.2.4 Appropriate physical format 308 8.2.5 Development of effective messages 309 8.3 Nonanthropomorphic Instructions 312 8.4 Display Design 315 8.4.1 Field layout 316 8.4.2 Empirical results 318
xiv Contents 8.4.3 Display-complexity metrics 320 8.4.4 Multidisplay design 323 8.5 Color 325 8.6 Practitioner's Summary 329 8.7 Researcher's Agenda 330 References 331 CHAPTER 9 Multiple-Window Strategies 335 9.1 Introduction 336 9.2 Individual-Window Design 341 9.3 Multiple-Window Design 349 9.4 Coordination of Multiple Windows by Tasks 357 9.5 Practitioner's Summary 362 9.6 Researcher's Agenda 362 References 363 CHAPTER 10 Computer-Supported Cooperative Work 367 10.1 Introduction 368 10.2 Goals of Cooperation 369 10.3 Asynchronous Interactions: Different Time, Different Place 10.3.1 Electronic Mail 371 10.3.2 Bulletin boards and conferences 374 10.3.3 File-transfer programs 376 10.3.4 Structured processes 377 10.4 Synchronous Distributed: Different Place, Same Time 378 10.5 Face to Face: Same Place, Same Time 382 10.6 Practitioner's Summary 388 10.7 Researcher's Agenda 390 References 391 CHAPTER 11 Information Exploration Tools 395 11.1 Introduction 396 11.2 String Search, Database Query, and Indexes 398 11.3 Flexible Search 401 11.4 Hypertext and Hypermedia 403 11.4.1 Author-system features 411 11.4.2 Authoring or editing hypertext 414 11.4.3 Creating the introduction 416 11.4.4 Converting existing documents and files 417 11.5 Multimedia: Videodisk, DVI, CD-ROM, and Beyond 418 11.6 Visual Approaches for Information Exploration 421 11.7 Graphical Boolean Expressions 423
Contents xv 11.7.1 Boolean expressions based on aggregation and generalization hierarchies 424 11.7.2 Filter-flow representation of Boolean expressions 426 11.8 Dynamic Queries 428 11.9 Tree-Maps 432 11.10 Practitioner's Summary 434 11.11 Researcher's Agenda 435 References 435 CHAPTER 12 Printed Manuals, Online Help, and Tutorials 439 12.1 Introduction 440 12.2 Reading from Paper versus Displays 442 12.3 Preparing Printed Manuals 444 12.3.1 Using the SSOA model to design manuals 445 12.3.2 Organization and writing style 447 12.3.3 Nonanthropomorphic descriptions 451 12.3.4 Development process 453 12.4 Preparing Online Facilities 455 12.4.1 Online manuals 457 12.4.2 Keyword and keystroke lists 460 12.4.3 Context-sensitive help 460 12.4.4 Online tutorials, demonstrations, and animations 461 12.4.5 Helpful guides 463 12.4.6 Natural-language and intelligent help 463 12.4.7 Experimental results 464 12.5 Practitioner's Summary 466 12.6 Researcher's Agenda 466 References 467 CHAPTER 13 Iterative Design, Testing, and Evaluation 471 13.1 Introduction 472 13.2 Participatory Design and Task Analysis 473 13.3 The Three Pillars of Design 475 13.3.1 Guidelines documents 475 13.3.2 User-interface management systems and rapid prototyping tools 477 13.3.3 Usability laboratories and iterative testing 478 13.4 Acceptance Tests 481 13.5 Evaluation During Active Use 482 13.5.1 Surveys 482 13.5.2 Interviews and group discussions 484 13.5.3 Online or telephone consultants 493 13.5.4 Online suggestion box or trouble reporting 494
xvi Contents 13.5.5 Online bulletin board 494 13.5.6 User newsletters and conferences 495 13.6 Quantitative Evaluations 495 13.6.1 Controlled psychologically oriented experimentation 13.6.2 Continuous user-performance data collection 497 13.7 Development Lifecycle 497 13.8 Practitioner's Summary 500 13.9 Researcher's Agenda 500 References 501 CHAPTER 14 User-Interface Development Environments 505 14.1 Introduction 506 14.2 Specification Methods 507 14.2.1 Multiparty grammars 508 14.2.2 Menu trees 509 14.2.3 Transition diagrams 510 14.2.4 Statecharts 514 14.2.5 User Action Notation (UAN) 514 14.3 Programming-Support Tools 517 14.3.1 Screen mockup and prototyping tools 518 14.3.2 Programming toolkits 519 14.3.3 User-interface management systems (UIMSs) 522 14.4 Design Tools for Evaluation and Critiquing 528 14.5 Practitioner's Summary 529 14.6 Researcher's Agenda 530 References 531 AFTERWORD Social and Individual Impact of User Interfaces Hopes and Dreams 536 Human Values and the Future of Technology 538 A Declaration of Responsibility 539 Ten Plagues of the Information Age 540 Preventing the Plagues 544 Overcoming the Obstacle of Animism 545 In the Long Run 548 Practitioner's Summary 549 References 549 Name Index 551 Subject Index 559