THE
HUMANE
INTERFACE
New Directions
for Designing
Interactive Systems
JEF RASKIN
.&.
TT
ADDISON-WESLEY
Boston • San Francisco • New York· Toronto· Montreal
London • Munich • Paris· Madrid
Capetown • Sydney • Tokyo· Singapore • Mexico City
CONTENTS
PREFACE
Xl
ACKNOWLEDGMENTS
INTRODUCTION:
Xlll
The Importance ojFundamentals
XVll
Background
Interface Definition
Keep the Simple Simple
Human-Centered Design and User-Centered Desrgn
Tools That Do Not Facilitate Design Innovation
Interface Design in the Design Cycle
Definition of a Humane Interface
2
2
3
4
5
6
Cognetics and the Locus ofAttention
2-1 Ergonomics and Cognetics: What We Carl: and Cannot Do
2-2 Cognitive Conscious and Cognitive Unconscious
2-3 Locus of Attention
2-3-1 Formation of Habits
2-3-2 Execution of Simultaneous Tasks
2-3-3 Singularity of the Locus of Attention
2-3-4 Origins of the Locus of Attention
2-3-5 Exploitation of the Single Locus of Attention
2-3-6 Resumption of Interrupted Work
9
9
11
17
18
20
24
27
29
31
ONE
1-1
1-2
1-3
1-4
1-5
1-6
TWO
vii
1
viii
CONTENTS
Meanings, Modes, Monotony, and Myths
3-1 Nomenclature and Notations
3-2 Modes
3-2-1 Definition of Modes
3-2-2 Modes, User-Preference Settings,
and Temporary Modes
3-2-3 Modes and Quasimodes
3-3 Noun-Verb versus Verb-Noun Constructions
3-4 Visibility and Mfordances
3-5 Monotony
3-6 Myth of the Beginner-Expert Dichotomy
THREE
FOUR
4-1
4-2
4-3
4-4
Quantification
Quantitative Analyses ofInterfaces
GOMS Keystroke-Level Model
4-2-1 Interface Timings
4-2-2 GOMS Calculations
4-2-3 GOMS Calculation Examples
4-2-3-1 Hal's Interface: Solution 1, Dialog Box
4-2-3-2 Hal's Interface: Solution 2, GUI
Measurement of Interface ffficiency
4-3-1 Efficiency of Hal's Interfaces
4-3-2 Other Solutions for Hal's Interface
Fitts' Law and Hick's Law
4-4-1 Fitts'Law
4-4-2 Hick's Law
Unification
5-1 Uniformity and Elementary Actions
5-2 Elementary Actions Cataloged
5-2-1 Highlighting, Indication, and Selection
5-2-2 Commands
5-2-3 Display States of Objects
5-3 File Names and Structures
5-4 String Searches and Find Mechanisms
FIVE
33
33
37
42
47
55
.59
62
66
68
71
71
72
73
76
77
78
80
83
87
90
93
93
96
99
101
103
105
109
115
117
124
CONTENTS
5-5
5-6
5-7
5-8
5-4-1 Search-Pattern Delimiters
5-4-2 Units of Interaction
Cursor Design and a Strategy for Making Selections
Cursor Position and LEAP
Applications Abolished
Commands and Transformers
ix
127
129
133
136
139
143
Navigation and Other Aspects of Humane Inteifaces
6-1 Intuitive and Natural Interfaces
6-2 Better Navigation: ZoomWorld
6-3 Icons
6-4 Techniques and Help Facilities in Humane Interfaces
6-4-1 Cut and Paste
6-4-2 Messages to the User
6-4-3 Simplified Sign-Ons
6-4-4 Time Delays and Keyboard Tricks
6-5 Letter from a User
149
150
152
168
174
177
178
183
184
187
Inteiface Issues Outside the User Inteiface
7-1 More Humane Programming Language Environments
7-1-1 System and Development Environment
7-1-2 Importance of Documentation in
Program Creation
7-2 Modes and Cables
7-3 Ethics and Management of Interface Design
191
192
192
SIX
SEVEN
Conclusion
APPENDIX A: The One-Button Mouse History
APPENDIX B: SwyftCard Interface Theory ojOperation
EIGHT
REFERENCES
INDEX
194
195
198
205
207
211
215
221
INDEX
About Face, 27
Absorption, 26
airplane crash and, 25
Accelerator pedal
interchanged with brake, 20
Accents, 186
Access permission
and invisible documents, 156
Accidents, 26-27
Actions
applying to objects, 59
Action-object, 59
Activated content, 104
Activations, 106
Adaption
adaptive menus, 57, 70
adaptive palettes, 57
Adjectives, 38-39
Mfordances
and visibility, 62-65
Aircraft
and buttons that change in the night,
51-52
Aircraft crashes
absorption related to, 25, 26-27
preventing, by eliminating a mode,
43--45
America Online
electtonic mail package, 41
AND
in search patterns, 174
Anderson,J. R., 12
APL, 186, 195
Apple Computer, 168, 172, 182
Apple iBook, 31
Apple Macintosh menu
and Fitts' Law, 94-96, 95
Apple Newton, 7
Apple H, 192
and SwyftCard, 211
Apple He, 169
Applications, 46
cognitive differences among, 104
as imposition, 148
liberating commands from, 100
similarity of, 101
software, xi
as visitors, 146-148. See also Interfaces;
Unification
Apricus, 157
Architecture, xi, 12
Argument, 76
Armstrong, Neil, 124
Ashlar pull-out palette, 58
Ashlar's Drafting Assistant, 40
Asimov, Isaac, 34
Atkinson, Bill, 209
Attention, 17ff
AutoCAD,40
Autoformat (Microsoft Word), 48
Automaticity, 20-21, 23, 28
Autopilots, 66, 67
Autorepeat, 36, 185
Awareness, 14-16
Baars, BernardJ., 11, 12,24,
27-28
Backspace command, 42, 43
Backward compatibility, 66
Bandwidth, 8, 87
BASIC, 192-193
221
222
INDEX
Bay Area Rapid Transit (BART)
and affordance avoidance, 64-65
Beginner-expert dichotomy myth, 68-70
Berra, Yogi, 19
Between-character cursor, '136, 138
Bibliographic icons, 173
Bifurcated interfaces, 91, 92
Bitmaps, 144
Bits
information measured in, 85
Block cursor, 136
Bob (Microsoft), 58
Boolean, 127, 139, 173n
Boot-up times, 7
Boustrophedonic scripts
delete cursor for, 138
Boyer-Moore algorithm, 129
bセvoLRPWXY@
Brevity
and clarity, 202
Browsers
"favorite locations" in, 152
zooming in on list of, 167
Bumgarner,John,185
Business JiVeek, 201
Buttons, 190
are fewer better?, 52-54
that change in the night, 51-52
C,167
C++, 167
Cables, 206
and modes, 195-198
CAD. See Computer-aided design
Calculation, 47, 72, 76-78, 89,
95,178
Calculator
versus computer, 141-142
Canon, 182
Canon Cat, 29-30, 30, 31, 50, 100, 121,
122,127,129,174,180
Calculate key built in, 142
disk formatting on, 182
ex-IBMers and testing, 174
"Local Leap" on, 138
and quasimodes, 56
Use Front key on, 56, 57
Caps Lock key, 39, 55
Card, Stuart K., 71, 76, 97
Cartoons,
emphasizing users' problems,
154-155.
"Case Against User Interface Consistency,
The" (Grudin), 189
Case studies
messages, 180
noun-verb flx to verb-noun problem,
60-62
Cathodes, television set, 7
Certiflcation
for interface technology, 201
Cervantes, Miguel de, 1
Chair ergonomics, 10
Character-at-a-time interaction, 130
Character efflciency, 89
Character sequences
need for sameness of, 127-128
Chaucer, Geoffrey, 87
Check box, 38, 39
Chord keyboards, 185
Chunking,37
Circular searching, 130, 132
City Slickers, 2
Clarity
and brevity, 202
of function, 70
and overuse of graphics, 172
Clark, Larry, 39
Click and drag technique,208
Clicking, 34
Climate-control mode, 51-52
Clip art, 172
Clockwork, 12
Close button, 106
Coaxial cables, 197
Cockpit, 25, 51, 66
Cognetics, 10, 12, 195, 205
and ergonomics, 9-11
and interface design, 168
and locus of attention, 9-32
Cognitive conscious, 13, 14, 205
and cognitive unconscious, 11-16
limitations of, 24
properties of, 16
Cognitive Theory qfConsciousness, A (Baars),
11
Cognitive unconscious, 11, 13, 14,205
habit-forming property of, 22
properties of, 16
Collaborative space
ZIP, 156
INDEX
Coior
display, 101
and icons, 170
palette, 171-172
Command key, 36, 171
Command line-driven systems, 50
Commands, 109-115
improved method of invoking, 111
liberating from applications, 100
and transformers, 143-148
and visibility, 112
Commands-plus-transformers computer
environment, 145
Comments, 194, 195
Composite selection, 107
Compound document, 140
Computer
boot-up times, 7
calculator versus, 141-142
crashes,S, 6
humane interface for, 102
problems, xix
and productive outcomes, 188
as servant, 189
user agitation and unexpected behavior
by, 27
and wasted time, 6
Computer-aided design, 40
Computer games, 63
Computer interfaces
cognetics and improvement in, 195
hardware comprising, 101
ConfIrmation steps
and fixed responses, 22-23
Conscious and unconscious, 15. See also
Cognitive conscious;
Cognitive unconscious
Consciousness
and models of the mind, 12-13
Consciousness Explained (Dennett), 12-13
Considerate programming
applications as visitors, 146-148
Content
defmed, 33-34
elementary operations on, 104
and quasimode, 59
structure as part of, 121
Control direction checks (RPVs), 44
Control functions
quasimodes reserved for, 59
Control principle, 183
223
Control sticks (RPVs), 43, 44
Copied content, 104
Copilot, 51
Copy command, 123
Cosmology, 15
Count-down clocks, 47
Crashes (computer), 147
Critical-path method GOMS
(CPM-GOMS), 72, 74
Crystal, Billy, 3
Cursors, 34, 105, 106, 209,212
Canon Cat and placement of, 31
design of, and making selections, 133-136
and Fitts' Law, 93-96
graphical design of, 133-136
and Hick's Law, 96
Insertion/deletion portions, 137
and LEAP, 136-139, 212
standard between-character, 133
two-part, 134
in Vellum, 40
Customer-centered design, 3
Customer feedback, 187-190
Custornizations, 48
Cut and paste, 177-178
DataViz, 145
Decay,
of sensory input, 18, 31
Decryption, 177
Dedicated numeric keypad, 90
Defaults, 190
Delays, 36, 184
Deleted content, 104
Delete key, 125
Deletion
humane design for, 178
Deletion of text
BRAVO methods for, 208
Delimited search, 125
Delimited-search dialog boxes, 132
Delimited searches, 126, 128, 129, 133
Delimiters, 76, 120
search-pattern, 127-129
Dennett, Daniel, 13
Design cycle
interface design in, 5-6
Design innovation
tools not facilitating, 4-5
Desktop-based computer systems, 31
224
INDEX
Diacritical marks, 186
Dialog boxes, 188, 189, 190
with check boxes for searches/launches,
131
with different launch buttons, 131
Digital fflter program, 144nll
Dilemma of preemption, 139
Direct perceptions, 18
Disambiguate, 126
Disappearing button, 51
DISK command, 181-182,213
Disk drives, 179
Disk formatting, 211
Displays
design of, 203-204
and ergonomics, 10
Display states of objects, 115-117
Distance
and Fitts' Law, 93, 94
Disturbance
and absorption, 27
Divide-by-O, 179
Documentation
importance of, in program creation,
194-195
Documents
compound, 140
Domain experts, 4
DOS (Disk Operating System), 213
Double clicking, 34, 74-75
Double quasimode, 109
Douglass, Frederick, 33
Drag-and-drop, 114
Dragging, 34, 106, 114
Duell, D.J., 22
Dynamic memory allocation, 118
Edsel,119
and absorption, 26
Efficiency
character, 89
and information, 85
measurement of with interfaces, 83-87
and thermodynamics, 84
Eject (a disk), 179, 181, 182
Electronic mail (e-mail), 176
America Online package, 41
Elementary actions, 103
cataloged, 103-117
commands, 109-115
display states of objects, 115-11 T
highlighting, indications, and selection,
105-109
and uniformity, 101-103
Elementary operations, 104
EMACS,125
E-mail. See Electronic mail
Embedded drawing programs, 140
Emotional needs, 58
Emperor's New Mind, The (penrose), 12
Empirical conscious, 11
Empirical unconscious, 11
Encryption, 177
Englebart, Douglas, 207
Environmental parameters, computer,
146
Equiprobable messages, 89
Ergonomics
and cognetics: what we can/cannot do,
9-11
Error messages, 27, 1セX@
transparent, 117
Error rate
of bifurcated converter, 92
Error reduction
and noun-verb interaction, 59
Errors
ambiguous notation and, 35
with double clicking, 74 ' •
mode, 40
with toggles, 39
Ethics
and management of interface design,
198,200-204
Eudora,100
Fast string search, 129
Feature bloat/complexity
decreasing, 146-147
Female connectors
on equipment/cables, 196
Female-to-female adapters, 196
Female-to-male adapters, 196
Fiber optics, 195
File names, 100
described, 118
eliminating, 119
and structures, 117-123
Files
and file names, 118
INDEX
Filters, 144nll
Fingerprints, 183
FireWire standards, 196
Fitts' Law, 71, 93-96, 97
and penalty with small targets, 138
and scrolling, 115
and standard text cursor, 133
Fixed delays, 184
Fixed responses
and confirmation steps, 22
Flashlights, 37-38, 46
Floppy disks, 182
Fluke oscilloscope, 52, 53
Focus, 108-109
versus locus, 17
Font size
and icons, 170
Footnotes
zooming in on, 156
Forward erase, 134
Four-conductor linear hermaphroditic
connector, 197, 198
Foveal, 17, 40, 135
-Fowles, Bob, 47
Freud, 11
Functionality
and simplicity, 202
Function buttons, 52
Fundamentals
importance of, xvii-xix
Games, 146
Generated content, 104
Gestures, 139
and comparative task analysis, 73
defined, 37
modal, 42
and monotony, 67
GIDs. See Graphical input devices
Global Village, 129
Goals, objects, methods, and selection rules.
See GOMS model
GOMS analysis, 206
and auto repeat, 185
GOMS calculation examples
Hal's interface: solution 2, GUI, 80-83
Hal's interface: Solution 1, dialog box,
78-80
GOMS keystroke-level analysis
for comparing GID and LEAP timings, 136
225
GOMS keystroke-level model, 72-83
GOMS calculation, 76-77
.
GOMS calculation examples, 77-83
interface timings, 73-75
GOMS model, 71
Grab cursor, 115
Graphical input devices, 34, 101,
103,212
buttons, 34, 143
comparative task analysis, 73
cursor moves with, 135
and double clicking, 74-75
and one-button mouse, 209
with two-part cursor, 138
and zooming, 164
and zoom quasimodes, 154, 155. See also
Cursors; Mouse
Graphical user interfaces, 2, 49,
122, 123
for Hal's interface, 81
Hal's interface: solution 2, 80-83
and icons, 170
searches initiated with, 129
Graphics, 119
Grey, C. G., 205
Grimes, Martha, 71
Grudin,J.,189
GUIs. See Graphical user interfaces
Habit formation, 18-20,21,22,213
Habituation, 205
and buttons, 52
and Hick's Law, 96
Hal,77-78
Hal's interfaces
efficiency of, 87-90
other solutions for, 90-92
Handheld computers, 7
Handheld personal data managers, xi
Handwriting tablet, 101
Hashing, 118
Heftman, Rex, 143
Heisenberg, Werner Karl, 83
Help systems, 175
Hermaphroditic coaxial connector
conductors for, 197, 200
Hermaphroditic connector-equipped
cables, 199
Hermaphroditic four-conductor connector,
197, 198
226
INDEX
Heuristics, 4
Hick's Law, 71, 96-97, 164
Hierarchical file structures
eliminating, 121
Highlighting, 105
Horn, Bob, 170
Horton, William, 169, 170, 172
Hospitals
ZoomWorld images of, 162, 163
Howard, Brian, 209
Human-centered design
and user-centered design, 3-4
Human-computer interfaces, 2. See also
Interfaces
Humane interfaces, 1
definition of, 6-8
ideal, 20
single ranges in, 46
techniques and Help facilities in,
174-177
and transformers, 144
typing in, 113
Humane programming language environments,192-195
importance of documentation in program creation, 194-195
system and development environment,
192-194
Human-machine design
and habit formation, 20
Human-machine interaction, xi
and quantitative methods, 72
Human-machine interfaces, xviii, 2
Fitts' Law applied to, 94
and locus of attention, 9
modal, 42
revolution in design of, 206
surmounting problems in, xii
iBook,31
IconBook, The (Horton), 169
Icons, 34, 63, 122, 168-174, 189
bibliographic, 173
particularly obscure, 169
Ieu. See Intensive care unit
!DE (Borland), 129
IEEE. See Institute for Electrical and Electronic Engineers
Implementation
influences on, 5
Incremental searches, 125-126, 128, 129,
132, 133
Indicated content, 104
Indication, 105-106
Information Appliance, 130, 133, 185
Information display
Tufte's principles of, 203
Information efficiency, 84
Information-theoretic efficiency, 84, 90
dialog box, 84
Information theory, 83
interface design related to, 87
Input devices, computer, 101. See also
Graphical input devices
Insertion of text
BRAVO methods for, 208
Institute for Electrical and Electronic Engineers,178
Intensive care unit
medical care chart used in, 157
ZIP view of, 158
zooming out beyond, 161
Interface-building tools, 4
Interface design, xi, 1, 71, 151
accommodating of human universalities,
68-69
Asimov's first law of robotics applied to,
6
and cognetic technology, 168
in design cycle, 5-6
estimating error rates from, 80
ethics and management of, 198,200-204
and habit formation, 22, 23
information theory related to, 87
and modes, 33
quantitative laws relating to, 93
ranking of performance times, 74
and sense perception, 18
simplifying, 100
and standards of practice, 201
without modes, 50
and ZUIs, 166
Interface designers, 3, 72
and beginner-expert dichotomy, 69
and development cycle, 200
and universal psychological facts, 4
and visibility, 63
Interface efficiency
measurement of, 83-87
Interface operation errors
preventing, 27
INDEX
Interfaces
and absorption, 26
definition of, 2
definition of humane, 6-8
and delays, 36
designing of, before implementing
interface design,S
and ergonomics of the mind, 10
and gesture, 37
and monotony, 67
nature of, 1
nonmodal,139
personality of user tailored to, 58
problems with, 187-188
quantitative analyses of, 71-72
to searches, 124-127
self-teaching, 175
simplicity of, 2-3
unified, 100. See also Humane
interfaces; Human-machine
interfaces; Interface design
Interface timings, 73-75
Interference, 21
Internet, xix, 12, 99, 153. See also World
Wide Web
Interrupted work
resumption of, 31-32
Intuitive interface, 149, 150, 151
Invisible Computer, The (Norman),
204
Invisible interface feature, 63
J, 195
. JavaScript, 126
Alert command in, 84
Jazz, 156n3
Jefferson, Thomas, 117
Jennings, Karla, 37
John, Bonnie E., 73
Joysticks, 34, 43, 103
Karpinski, Dick, 18
Kay, Alan, 141
Keyboards, 101, 109-111
design, 11
and ergonomics, 10
full-chord, 109
interfaces, 36
shortcuts based on, 67
227
time delays and tricks with, 184-187. See
. also Cursors; Mouse
Keystroke-level model (GOMS), 72
Keyword, 174, 175
Knobs, 63
Knuth, DonaldE., 194, 195
Labels
clarity preferred over brevity in, 167
icons versus, 170
on mouse buttons, 209
visibility enhanced by, 51
Landauer, Thomas K., 139
Landmarks, 152, 153, 154
Language conventions
bending machine to, 113
Launch buttons, 130
dialog box with different, 131
Lazar, David, 11
LEAP, 129, 135, 155, 168, 175, 204
and cursor position, 136-139
document selection with, 122
superiority of, 139
LEAP AGAIN, 138
LEAPing, 138
Learning times
and natural GO MS language, 72
Left-to-right languages'
delete cursor for, 137-138
Legended buttons, 51
Lewis, Thomas, 19
Lightpens, 34
LISp, 195
"Local Leap;' 138
Lock command, 116
Locked text
and typing; 175-176
Lock with Password command, 116
Locus of attention, 17-32, 43, 109, 205
and choice of methods, 67 .
execution of simultaneous tasks, 20-23
exploitation of single, 29-30
focus collocated with, 108
and formation of habits, 18-20
and habituating features, 57
and launch buttons, 131
and modality of interface, 42
and mode, 40, 41
and noun-verb interaction, 59, 60
origins of, 27-29
228
INDEX
resumption of interrupted work, 31-32
and side effect, 113
singularity of, 24-27
Lower-cost software packages .
failure of, 145
Machine response times
and user actions, 75
Macintosh computer, 172, 200, 207
and one-button mouse, 209
resetting RAM parameter on, 36
Macintosh interface
delays with, 184
guidelines, 4
Macintosh operating system, xi
Macro, 46
Macromedia Flash, 167-168
Magnetic-resonance imaging, 15
Male connectors
on equipment/cables, 196
Male-to-female adapters, 196
Male-to-male adapters, 196
Management
of interface design, 198, 200-204
Manhole, The, 150
Markoff process, 87
Martin, Pam, 75nl
Masking, 30
Mathematica, 195
Maxwell, James Clerk, 72
May-hew, Deborah, 72, 170
Mazes
antithesis of, 152
Meaning
and information, 86-87
Measures of efficiency, 71
Medical care charts
zooming in on, 159, 160
Memory, 14,32. See also Locus of attention
Mental operators
heuristics for placing, 76-77 (table)
Menus, 34, 50, 110, 112, 190,212
adaptive, 57
experiments on structures of, 97
systems based on, 67
Merchantability
denials of, 201
Messages
measurement of information embodied
in, 86
user, 178-183
Messerschmidt, Willy, 6
Microphones, 101
Microsoft Office, 143
Microsoft Windows menu
and Fitts' Law, 94-96, 95
Microsoft Word, 23, 47, 49, 100
search box, 128
set-up-then-launch dialog box in, 131
Mill, John Stuart, 150
Mind
consciousness of, 12-13
ergonomics of, 10
Mobile Office magazine, 2
Modal design, 50
Mode errors, 40, 55
frequency of, 40
minimizing, 41
Modeless interfaces, 67, 68,206
Modelessness, 46
Model-search dialog box, 124
Modes, 33, 37-42, 205
aircraft crash prevention through elimination of, 43-45
and cables, 195-198
definition of, 42-43
elimination of, 212
error reduction and elimination of, 209
and quasimodes, 55-59
Modified content, 104
Monotonous interface, 67, 68
Monotony; 33, 66-68, 206, 213
Moran, Thomas P., 71, 76, 97
Mouse, 34, 151
double clicking, 74-75
grab function on, 115
for working with ZIp, 168
Move command, 123
Moved content, 104
MRI. See Magnetic-resonance imaging
Multiple-character commands, 50
Multiple-line comments, 194
Multiple-option switches, 46
Multiple-pin connectors, 197
Nass, Clifford, 68
Natural GOMS language, 72
Natural interfaces, 150, 151
Natural language, 120
conventions, 113
INDEX
NaVigation, 149
white space versus, 202-204
ZoomWorld,152-168
Newell, Alien, 76, 97
NextWave (tIP), 140
NGOMSL. See Natural GOMS language
N-key rollover, 186, 187
Noik, Emanuel, 164
Nomenclature
and notations, 33-36
Nonkeyboard devices, 87
Nonmodal interfaces, 139
Nonvolatile memory, 32
Norman, Donald, 12,40,41,72, 156n3,
204
Notations
ambiguous, 35
and nomenclature, 33-36
Noun-verb constructions
versus verb-noun constructions, 59-62
Noun-verb design of commands, 213
Oberon,194
Objects
actions applied to, 59
display states of, 115-117
highlighting of, 105
and locus df attention, 109
sameness for, 102
OCR programs. See Optical character
recognition programs
Old selection, 106
OLE software (Microsoft), 140
One-button mouse, 34
history and future, 207-209
One-on-one interaction with human user
ease and pleasantness of, xix
OpenDoc (Apple), 140
Operating system, xviii
elimination of, 212
Optical character recognition programs,
.
144
Oscilloscopes, 169
Overlapping windows, 141
Overstriking, 187
with quasimode, 186
Pace of interaction
user setting of, 8
229
PAD++,156n3
Paddle switches, 45
Page breaks, 120
Paint programs
and noun-verb interaction, 60
Palm Pilot, 7, 102
Parallel processing, 28
PARC cursor, 138
PARC (Palo Alto Research Center), 141,
207,209
Passwords, 183-184
Patterns, 124
in searches, 133
Penrose, Roger, 12, 24
Perceptual memory, 18
Perl, 167
Persistence of vision, 18
Personalization features
time wasted in learning/operating, 48-49
PET. See Positron-emission tomography
Photo-processing programs, 104
PLlI,195
Positional cues, 152
Positron-emission tomography, 15
Pound, Ezra, 66
Power connectors, 197
Preemption dilemma solution, 139-140
Preferences, 47
Pressure-sensitive graphic tablets, 103
Product
interface as, 5
Productivity
designing for, 5
Programmers, 193
and documentation, 194-195
Programming
considerate, 146-148. See also tIumane
prograrnining language environments
Progress bar, 76
Psi effect, 153
Psychology of Computer Programming (Weinberg),195
Pushbuttons, 63
Quantification, 71-97
Fitts' Law and tIick's Law; 93-97
GOMS keystroke-level model, 72-83
measurement of interface efficiency,
83-92
quantitative analyses of interfaces, 71-72
230
INDEX
Quantitative guide
for improvement, 92
Quasimodal,55
Quasimodes
and modes, 55-59
overstriking with, 186
for searches, 129
Querying, 104
Radio
truck, 53, 54
Radio buttons, 38-39
dialog box solution with, 79
labeling with adjectives, 39
Radio-controlled model aircraft, 43
Ranking
of performance times of interface
designs, 74
Rating systems
interface-quality, 202
Redo command, 107, 108
Redo key, 108
Remote-piloted vehicles, 43
commercial controller, 43
switch handles on, 45
Repetitive stress injuries, 201
Resetting computer programs, 148
Reversibility
and noun-verb interaction, 60
Right-to-left languages
delete cursor for, 138
Robinson, Spider, 109
Robotics
Asimov's first law of, 6
Rollover, 186, 187
RPVs. See Remote-pi.J.oted vehicles
RSI. See Repetitive stress injuries
Saving work, 5
Scanning, 144
Scope of activity
and modes, 45
Screen Lock command, 116
Screen Unlock command, 116
Scrolling, 114, 133, 164,209
replacement for, 115
SCSI connections, 196
Searches
interface to, 124-127
Search-pattern delimiters," 127-129
Search quasimodes, 129
Security
and sign-ons, 183-184
Selected content, 104
Selecting, 106
Selection, 106-107
separating drag gestures from, 114
transparency of, 116-117
Self-teaching interfaces, 175
Separators. See delimiters.
Separator characters, 120
Servo
in RPV; 43, 44, 45
Sex-changing adapters, 196
Shakespeare, William, xiii
Shannon, Claude E., 86
Shaw, George Bernard, 198
Shift key, 35
Shneiderrnan, Ben, 72
Short term memory, 28n4, 63
and toggles, 39
Side effect
eliminating, 113
Sign-ons
simplified, 183-184
Simplicity, 70, 100,205
factors supporting/working against, 202
and noun-verb interacti<m, 60
with tasks, 2-3
Sims, Admiral William S., 149
Simultaneous tasks
execution of, 20-23
Single personhood, 28
Single-use interface design, xix
Sleep mode, 7, 50
Smalltalk, 167, 195
Smith, S. F., 22
SNOBOL,195
Snow, C. P., 2
Software
licenses, 201
selling on command-by-command basis,
144
unused features of, 145
Sony,182
2010 short-wave radio, 54
Sound files, 119
Space bar, 35
Space-making tactics
with ZoomWorld, 155
INDEX
Special characters, 128
Spector, Lincoln, 139
Speech recognizer, 101
Speed
of incremental searches, 129
and information efficiency, 85
with LEAP, 135
and noun-verb interaction, 59
Spell checking, 102
Spreadsheets, 104, 177
Spring-loaded mode, 55
Spring-locked mode, 55
SRI. See Stanford Research Institute
Standards of practice, 201
Stanford Research Institute, 207
Stanley Steamer, 7
Steam-powered automobile, 7
STM. See Short term memory
Strachey, C., 99
String, 76
defined, 124
String searches, 124, 133
fast, 129
and find mechanisms, 124-132
Structures
and file names, 117-123
Subjective ratings
and interfaces optimizing productivity,
49
Swinehart, Dan, 139
SwyftCard
interface theory of operation,
211-213
sセケヲエv。イ・L@
121, 129, 138, 174
Syntax
for commands, 113
System and development environment,
192-194
Tables
and ergonomics, 10
Tablet pens, 34
Tap, 34, 35
Target, 124
and Fitts' Law, 93, 94
Task analysis
comparative, 73
Task definition, 5
Task domain experts, 4
Tektronix oscilloscope, 53
231
Telephone voice-response system, 2
Television sets, 7
Temperature-conversion, 77-83, 87-92
Temperature converter, 81
Temporary modes, 49
Tesler, Larry, 141
Testing, 170, 213
Text, 124
BRAVO and insertion/ deletion
of, 208
commands for changing, 116
and cut and paste, 177-178
drag-and-drop in, 114
encrypted, 177
as visual cue, 170, 189. See also Visibility
Text-editing rules
universal, 99
Text editors, 140
Text file
content of, as best name for, 119
Text pointing
with GIDs, 135
Thermodynamics
efficiency defined in, 84
Thermometer, 80-83,81
Thompson, D'ArcyVVentworth, 71, 73
Ticket machines, 64-65
Time
sacredness of, 5-6
Time delays, 30
and keyboard tricks, 184-187
Toggles, 39, 46, 108
labeling difficulties with, 38
Touchpads, 34, 209
Touch screen, 101
Tracer
in Vellum, 40
Trackballs, 34, 209
Transformed content, 104
Transformers
and commands, 143-148
and vendors, 145
Transparent dialog box, 117
Truck radio, 53, 54
Tufte, Edward, 203
Tullis's restrictions, 204
Twain, Mark, 178
Two-part cursor, 134, 138
Typing
accents, 186
commands, 116
232
INDEX
and locked text, 175-176
and selection, 110-113
speed, 74. See also Text
UCSD Pascal, 194
UML Toolkit, 5
Unamuno, Miguel de, 19
Unconscious
and conscious, 15
Undefined value, 178-179
Undo command, 107, 108, 109
Undo key; 108
Unification, 99-148
applications abolished,
139-142
commands and transformers,
143-148
cursor design and strategy for making
selections, 133-136
cursor position and LEAP, 136-139
elementary actions cataloged, 103-117
file names and structures, 117-123
string searches and [rod mechanisms,
124-132
uniformity and elementary actions,
101-103
Uniform Commercial Code, 201
Uniformity
and elementary actions, 101-103
Unit of input
program interaction with smallest,
129-130
Units of interaction, 129-132
Unlock command, 116
Unlock with Password command, 116
URLs,206
USB standards, 196
User-centered design
and human-centered design, 3-4
User interfaces, 2
fundamental flaws in, xi. See also
Interfaces
User interface theory of operation
and SwyftCard, 211
User-maintained mode, 55
User messages, 178-183
User preference settings, 47, 48
User(s)
letter from, 187-188
pace of interaction set by, 8
Variable-legend buttons, 52
VCR
easy-to-set digital clock on, 3
Vellum, 40, 49
adaptive palette for, 57
Vending machines, 64
Vendors
and transformers, 145
Verb-noun constructions
versus noun-verb constructions,
59-62
Vertically oriented languages
delete cursor for, 138
Veteran's Administration Hospital
(palo Alto)
LEAP testing at, 135
Video inputs, 101
Visibility, 70
and affordances, 62-65
and commands, 112
and icons, 168, 174
labels enhancing, 51
lack of, 107
Visible interface feature, 62
Visual Basic, 4, 126, 193,
194-195
Visual C++, 4
Voice-controlled systems
LEAP usefulness in, 135.
Voiceprinting, 183
Weaver, 86
WEB, 195
Web pages, 31
and higher-bandwidth communication
channels, 8
programs, 104 .
Web sites, xi
Weinberg, Gerald M., 195
Whitehead, Alfred North, 191
White space
versus navigation, 202-204
Whole-text searches, 119
Wildstrom, Steve, 201
William of Occam, 101
Windowing paradigm, 141
Windows interface guidelines, 4
Windows operating system, xi
Windows 2000 (Microsoft)
adaptive menus in, 70
INDEX
Wi:nter, James, 180, 181, 182
Word processors, 31, 104,
140,212
Work
sacredness of, 5-6
World Wide Web, 12
surfmg in ZoomWorld, 164
zooming in to one area of, 166
ZoomWorld portal to, 165
Xerox PARe. See PARe
ZIP. See Zooming interface
paradigm
Zooming in, 154
Zooming interface paradigm, 153
browser replaced by, 164
working effectively in, 156
Zooming user interfaces,
166,206
Zoom quasimodes, 154
ZoomWorld,152-168
ZUIs. See Zooming user
interfaces
233