Organized Activity and its Support by Computer

198 Pages·1997·11.719 MB·English

by  Anatol W. Holt (auth.)

Organized Activity
and Its Support by Computer
Organized Activity
and its Support by Computer
by
Anatol W. Holt
SPRINGER-SCIENCE+BUSINESS MEDIA, B.V.
A C.I.P. Catalogue record for this book is available uom the Library of Congress
ISBN 978-94-010-6357-9 ISBN 978-94-011-5590-8 (eBook)
DOI 10.1007/978-94-011-5590-8
Printed on acid-free paper
AII Rights Rcscrved
e
1997 Springer Science+Business Media Dordrecht
Originally published by Kluwer Academic Publîshers in 1997
Softcover reprint of the hardcover Ist edition 1997
No part of the material protected by this copyright notice may be reproduced ar
utilized in any ronn or by any means. electronic or mechanical,
including photocopying. recording ar by any information starage and
retrieval system, without written permission rrom the copyright owner.
There is more under heaven
than is dreamed of in your
philosophies, Horatio
William Shakespeare,
Hamlet
Contents
FORWORD and acknowledgements ........................................................... ix
PREFACE. ................................................................................................... xi
CHAP1ER 1 _ INTRODUCTION ............................................................. 1
1.1 Coordination in practice ......................................................................... 5
1.2 Computers .............................................................................................. 7
1.3 Social machines ..................................................................................... 9
CHAP1ER 2 - PREPARATIONS ........................................................... 13
2.1 Technical languages ............................................................................. 14
2.2 Diagrammatic languages ...................................................................... 17
2.3 Units .................................................................................................... 19
2.4 Units, complex units, and the Theory .................................................. 23
2.5 Units and related theories ..................................................................... 24
CHAP1ER 3 - ACTIONS, PERFORMERS.(theory) .............................. 27
3.1 Actions, performances, performers ..................................................... 28
3.2 Interests ............................................................................................... 31
3.3 Units for the management of failure .................................................... 33
3.4 Why machines do not perform actions ................................................ 36
3.5 Summary and forward pointers ............................................................ 39
CHAP1ER 4 - ACTIONS, EFFECTS (theory) ....................................... 41
4.1 Things (bodies), and actions ................................................................ 42
4.2 Types of effects ................................................................................... 44
4.3 More on states and state changes ......................................................... 49
4.4 Action, solo action, and interaction ...................................................... 52
4.5 A brief overview of Chapters 3 and 4 ....... '" ........................................ 55
4.6 On the vagueness of boundaries ........................................................... 56
CHAP1ER 5 - THE PULSAR (vision) ................................................... 61
5.1 Getting organized activity support in focus ......................................... 61
5.2 Pulsar generalities ............................................................................... 62
5.3 Electronic meetings .............................................................................. 67
5.4 Document production ........................................................................... 70
5.5 Software development.. ....................................................................... 70
5.6 Pulsar complexes, etc .......................................................................... 73
5.7 The Theory so far as related to the Pulsar. ........................................... 74
CHAP1ER 6 - PLAN AND DIPLAN (theory) ........................................ 79
6.1 Plan generalities ................................................................................... 79
6.2 Scenarios, stories, and multiplicities .................................................... 81
6.3 Plans and their scenarios ...................................................................... 87
6.4 More on plans, their scenarios, and cuts .............................................. 93
6.5 The Pulsar revisited .............................................................................. 95
Vlll
CHAPTER 7 - IGO (vision) ................................................................... 103
7.1 Two axes of coordination .................................................................. .103
7.2 Material vs. activity organization ...................................................... 106
7.3 From a standard operating system to Igo ........................................... 108
7.4 Igo and storage ................................................................................... 115
CHAPTER 8 - INFORMATION (theory) ............................................. 119
8.1 Generalities ........................................................................................ 119
8.2 Preliminaries ...................................................................................... 121
8.3 Decision ............................................................................................. 125
8.4 Timing and information ..................................................................... 128
8.5 Stepping back from the details ........................................................... 130
8.6 Information flow in state machines .................................................. .133
CHAPTER 9 -STORES (vision) ............................................................. .139
9.1 Generalities ........................................................................................ 139
9.2 Stores and computers ......................................................................... 142
9.3 Databases and sharing ........................................................................ 146
9.4 Some (surprising) relationships to the Theory ................................... 148
CHAPTER 10 - THE VISION AS A WHOLE ...................................... 151
10.1 From a standard operating system to Igo ......................................... 152
10.2 Centropolies and Igos: a new e-world ............................................ 156
10.3 World-wide coordination ................................................................ 157
CHAPTER 11 - THE THEORY AS A WHOLE ................................... 163
11.1 The Theory and science in general... ............................................... 164
11.2 Pure vs. applied ............................................................................... 166
11.3 "Science" about human behavior.. ................................................... 166
11.4 "Pre-mathematical"? ...................................................................... 171
11.5 State and prospects .......................................................................... 173
APPENDIX A: Information, and state machine structure ........................ 175
APPENDIX B: Petri nets, and related Diplan exercises ........................... 181
Cumulative bibliography ................................................................. 191
Analytical index ............................................................................... 195
Foreword
and Acknowledgements
Why this book? There are too many books already. But there is a paradoxical
connection: this book exists because there are too many books already. The
computer is responsible for the avalanche of goods and the dirth of jobs.
Indirectly, if this were not so, this text would not have been written.
I count the computer as one of the most trenchant and formative expe
riences of my life. We met in 1952, the very year in which the computer went
commercial - at $1,000,000 a shot. Like one of Lorenz's ducklings, I was
"imprinted" .
First, I understood at once: the computer was destined to change what it
meant to be a human being on earth. Already now - only 45 years later -
this early intuition is turning into present reality. (Only yesterday Deeper
Blue beat Kasparov at chess!)
Second, I was struck by a puzzle. Like so many other technologies, the
computer was a child of War. In that context it was supposed to help carry out
extremely tedious calculations, which would lead to numbers, which would
lead to more fire power against the enemy. It was supposed to compute -
which is why it was called a computer. But: very few of the potential cus
tomers for the new machine on the market had problems of this type. Instead,
they used it for sorting data" controlling railroad traffic, issuing paychecks,
etc.
In my young mind this raised a burning question: if the computer was
not really - or mainly - for computing, then, what was itfor? The right
answer to this question, I thought, is crucial to understanding - and
therefore controlling - the "computer revolution" to come. Today I think:
perhaps the "computer revolution" is too big to be controlled by anything or
anyone; but the question is as luminous (and infuriatingly difficul) as ever.
Nevertheless, this question may (rightly) seem impractical to you.
Regardless, the main point of this book is not philosophy: it is to give you
more "fire power" - if your business seriously involves the computer, and/or
human organization. That is why I have allowed myself to write a book that
takes work to read - here and there with sugar on the pill. Perhaps this book
is supernumerary; but I hope it is still in time to contribute -to you, and to
us.
I am deeply grateful for the generous research support that I received
over a period of more than a decade (1964 - 1974) from the United States
Department of Defense, and more specifically from the Advanced Research
Projects Agency, IPTO, then under the leadership of Ivan Sutherland, and
ix
later, Larry Roberts. I took a lot, and gave back little. I truly hope this book is
some compensation.
The person who has made the (overwhelmingly) greatest contribution to
the substance of this work is my friend and colleague Carl Adam Petri, for
merly of the Gesellschaft rur Mathematik und Datenverarbeitung, Bonn,
Germany. I have learned from him, and fought with him over decades.
This book was written in Italy in course of the last 4 years. During that
time I have received much encouragement and support at the Dipartimento di
Scienze della Informazione of the University of Milano, notably from Giorgio
De Michelis, and Gianni Degli Antoni. Giorgio, as professor in charge of
computer support for cooperative work (CSCW), has encouraged me, and
helped me on numerous occasions, including preparation of the manuscript.
However, no one at the University has has been as close to me as Felice
Cardone - a young researcher with a fine mind, the meticulousness of an
excellent programmer, and a kindred spirit. He has given generously of his
time and effort.
Another person who has helped me a lot - with advice, critique,
manuscript preparation, moral support, etc. is Terry Winograd - professor of
computer science at Stamford University. Terry has been my friend for years.
Although we look at the world quite differently, he is the only other person I
know with objectives similar to mine. I especially appreciated his help,
knowing his schedule.
I am also grateful to Kluwer Academic Publishers, and more especially
to Polly Margules and Laura Walsh, for their part in this book enterprise.
Last but not least, there is Prof. Anastasia Pagnoni, mathematician, com
puter scientist, my wife. She prodded me to write this book, and she more
than anyone has suffered the consequences. Without ARPA, without Carl
Adam Petri, and without Anastasia Pagnoni there would be no book.
Since this work stretches over most of my professional life, there are in
numerable individuals and agencies that should be recognized and acknowl
edged. Thank you all.
Anatol Holt
Milano, May 1997
Preface
by Terry Winograd
I first encountered Tolly Holt more than thirty years ago, when he and a
young colleague presented a seminar at the MIT Artificial Intelligence Labo
ratory, which I had just entered as a graduate student. Even though the event
was in most ways unremarkable - just another in a long line of seminars -
it made a deep and lasting impression on me. When I reconnected with Holt
many years later, the reasons for that impact were rekindled.
First, Holt displayed a level of passion and involvement that was not ex
pected in a seminar on the arcane formal theory of automata. Although the
work itself was dense and mathematical, it was clear that he cared about it
with a full-blooded concern that was far from "academic." What he was doing
mattered to him, and he wanted it to matter to the world.
Further, the way in which the theory mattered was in its application to
the real world in which people lived and worked. A culture clash was evident
at that meeting. We at the Artificial Intelligence Lab were engaged in a kind
of science fiction endeavor - trying to create machines that would be as in
telligent as people. We had little patience for the more "mundane" concerns
of using machines to facilitate what people do in their everyday activities.
Holt, on the other hand, was grounded first and foremost in an understanding
of people and what is meaningful to them. Years later I read a paper of his
containing an insightful remark that I have since often repeated. Imagine, he
said, a computer program that is able to calculate a brilliant chess move while
the room around it is catching on fire. That is an example, says Holt, of what
truly deserves to be called "artificial intelligence".
The present book is a culmination of a life of work that exemplifies these
two characteristics of Tolly Holt: intellectual passion, and a concern for what
matters to people. In the years since that early seminar, Holt has been a partic
ipant in the computing world at every level, from managing computer sys
tems to developing commercial software to publishing theoretical articles in
academic journals. His breadth of knowledge and experience makes possible
the interweaving of theory and practice that shapes the fabric of the book.
People often make a false opposition between theory and practice. In this
case, it is a synergy: practice guides the theory, and the theory is grounded in
its application.
Readers from a computer science background may well find the book a
bit odd. It does not draw all of the connections that could be made to work by
many other computing researchers, and it is not written from the point of
view of a "native." Holt has lived with the computing community for many
xi
xii PREFACE
years, but he maintains the perspective of an outsider: not the kind of outsider
who is an immigrant trying unsuccessfully to blend in, but rather the kind of
outsider represented by an anthropologist. Even after years of living and
studying as a participant-observer, the anthropologist maintains a perspective
in which the everyday life of the natives is always kept "strange" - open to
critical observation and reexamination. The anthropologist's question "What
are they doing now?" is not a request for a detailed description, but a quest for
deeper significance. Holt asks this question of computational practice. He
wants to understand what we are really doing when we design and work with
the myriad of interconnected computer systems that make up today's every
day world.
The answer Holt comes up with will be surprising to many readers. De
spite their name, computers are not devices whose purpose is to compute.
They are devices to coordinate human activity. My first response to this claim
was skeptical (as I suspect it will be for many readers). Of course, some com
puters are used for the coordination of human activity, but what about all the
other things computers do, from spreadsheets and word processors to video
games, virtual reality, and controllers for microwave ovens? Holt's response
comes from the clarity and directedness of his vision. Of course computing
devices do all sorts of detailed tasks that may not look like human coordina
tion on the surface. But underneath every use of computing, we find people
with individual and organizational concerns and purposes. Their activity as
they use and encounter computers is what maners. It is these concerns that
give shape and content to the innumerable tasks that computers perform. We
can analyze the structure of the underlying human activities in a systematic
way, and there is great power in viewing all computation from that perspec
tive.
Readers will also find the book unusual in its mixture of styles, from the
charming eloquence of the motivating discussions to the dense technical
analysis of detailed diagrams of activity. Not every reader will be motivated
and able to follow every section. But, as Holt points out in the Introduction,
there is value to be gained at many levels. The detailed analysis can lead to
the understanding of practices (and to the design of new practices) that have
direct applicability in the development of computer systems. At the same
time, the theoretical perspective, even without the detail, can give every
reader new ways to look at the computing world and the larger human world
in which it is embedded.
Holt's major contribution is his new perspective on what we in the com
puting field have been doing for so many years. He shifts the focus of under
standing, and in doing so, he opens up new possibilities for creating tech
nologies that can playa significant and positive role. This book conveys the
intellectual challenge and the passion that Holt brings to this new perspective
- to situating computing in the realm of human activity, human coordina
tion, and the living of our lives.
Terry Winograd
Palo Alto, May 1997