(ref.doc)pd111095

Date: Wed, 11 Oct 1995 09:30:23 -0500
From: Fred Ballard <[email protected]>
Subject: Re: Who discovered Alexander?

---------- Forwarded Message ----------

From:	Larry Constantine, 72067,2631
TO:	Fred Ballard, 72400,1525
DATE:	10/9/1995 11:09 PM

RE:	Copy of: Re: Who discovered Alexander?

Thanks for CCing me on that one. Please pass this note on to the group.

It is funny how these stories can build up. Now days, Alexander is
being credited for everything! It is possible that I introduced Ed to
the Alexander book, but I don't think so. I certainly did introduce
him to structured design, but Alexander, no doubt an original thinker,
had nothing to do with the development of coupling and cohesion, at
least in terms of my work. In any event, I think Ed was more
enthusiastic about Alexander than I was in those days.

The notion of intercomponent coupling was well-established in general
systems theory, which I was introduced to as an undergrad at MIT. I
just took the concept and built an applied theory in the realm of
software architecture. Cohesion comes from the human sciences and
shows up in the concept of group cohesion in sociology as well as in
the notion of coherence in cognitive psychology. Again, I just built
the intermediate-level applied theory in the domain of program
structure. The term was originally "cohesiveness" as used by one of my
early mentors, Ken Mackenzie. Both constructs were well-developed by
the time I wrote a paper for the National Symposium on Modular
Programming in 1968. The "brand name" of structured design was
supplied later by IBM through Wayne Stevens for the 1974 paper in the
IBM Systems Journal. Much of the earliest work on structured design
was not published, in part because I couldn't get anything past the
journal referees. I finally had an article published in Communications
of the ACM decades later, although it was on organizational and team
dynamics!

My current research activities involve extending the constructs of
coupling and cohesion into the domain of user interface architecture.

--Larry Constantine
Professor of Computing Sciences
University of Technology, Sydney
[email protected]