edge (e.g., books, appliances,
electronics, games), giving us a
much higher level of both coherence and responsiveness.
Again, these systems succeed
because they are “permeable” to
user preferences and judgments,
while still filtering and organizing
them. Review aggregators need
more active curation than Internet
search engines. However, they
have delegated some of that curation to users, by aggregating feedback on reviews as well.
Online collaboration systems. The
Internet has catalyzed the emergence of very large open working
groups, such as the Linux development community, the Wikipedia
authoring community, and various
fan and support groups. There
have been open working groups
in the past—in some sense any
academic discipline is such a collaboration—but these new groups
are larger, more open, and work
These groups are possible due
only to collaboration mechanisms
such as mailing lists and their
archives, wikis, ticketing systems,
and version management. These
help maintain both the coherence
and the responsiveness of groups
that are too large or dispersed for
older modes of coordination.
Consider version management.
It is interesting because it has
evolved considerably in the recent
past, is still evolving fairly quickly,
and its role in moving to higher
trade-off curves has been explicitly discussed by its users.
For example, Wikipedia invites
any visitor to edit most Wikipedia
pages. This is only sustainable
because the version management
built into the software platform
(Mediawiki) allows rapid reversion
(undo) of inappropriate edits, help-
ing a huge collaborative editing
project sustain both high respon-
siveness and high coherence.
any feature into a service requires
assumptions about how people
will use it; the fewer such assumptions, the wider the range of users
and uses that can be accommodated gracefully.
We believe there are many ways
to simultaneously increase the
coherence, responsiveness, and
scalability of systems, and this
quest has enormous potential to
improve our lives.
1. Harris, J. and Henderson, A. A better mythology
for system design. Proc. of CHI ‘99. ACM, New
York, 1999, 88-95. DOI= 10.1145/302979.303003;
2. Yates, J. Control through Communication: The
Rise of System in American Management. The Johns
Hopkins University Press, 1993.
3. Henderson, A. The 100% solution: What is a user
to do, and how are we helping? Proc. of the 15th
European Conference on Cognitive Ergonomics:
the Ergonomics of Cool Interaction. J. Abascal, I.
Fajardo, and I. Oakley, eds. ACM, New York, 2008.
4. Henderson, Jr., D. A. The Trillium user interface
design environment. Proc. of CHI ‘86. M. Mantei
and P. Orbeton, eds. ACM, New York, 1986, 221-
227. DOI= 10.1145/22627.22375; http://doi.acm.
5. Raymond, E. The Cathedral & the Bazaar:
Musings on Linux and Open Source by an Accidental
Revolutionary. O’Reilly Media, 2001.
ABOUT THE AUTHORS
Jed Harris started out exploring
cultural anthropology, linguistics,
philosophy of science, and artificial intelligence research, and
then spent 40 years in research
and development at SRI,
Austin Henderson’s 45-year
career in HCI includes research,
design, architecture, product
development, and consulting at
Lincoln Laboratory, BBN, Xerox
(PARC and EuroPARC), Fitch,
Apple, and Pitney Bowes. He
focuses on technology in conversations in a rich
and changing world.
As these examples show, even very
large systems can be both coherent and responsive. Furthermore,
in many cases they can achieve
both apparently conflicting goals
using a relatively simple and slowly evolving service platform.
One theme is that the technical
systems are permeable to human
meaning, values, and choices—
they encourage communication
between their users, coordinated
by the infrastructure.
A second theme is that each service is focused on relatively simple
ways of handling a relatively
small set of functions. Building
September + October 2012
© 2012 ACM 1072-5520/12/09 $15.00