Computer Systems Laboratory Colloquium

4:15PM, Wednesday, November 29, 2000
NEC Auditorium, Gates Computer Science Building B03

The missing link in software pattern theory.
Generative sequences as the next breakthrough in programming.

Christopher Alexander
About the talk:

Professor Alexander will address the road he has followed in the last years that have taken him from patterns to sequences. A generative sequences is a semi-algorithm, a flexible system of instructions which lay out for the user which decisions need to be made in which order. Decision A becomes the context for Decision B and when the sequence is a good one, the morphology of the resulting design unfolds naturally, reaching a coherent though highly complex and subtle structure. No backtracking is necessary. In mainstream architectural practices, thee are requirements for plans and blueprints which force premature decisions which then become contractually binding and costly to correct. Generative sequences allow for a more organic unfolding, much as an embryo unfolds, each stage preserving essential characteristics of the previous stage, and each stage having "wholeness" in and of itself.

The discussion will also address the issue of protected programs or sequences and open/shared programs and the ethics of websites such as

If you are planning to attend the session, you may wish to take a look at the website . In particular, there is a demo and worked example of a short sequence which takes you through the decision steps in designing an entrance transition. For the enthusiastic (or sleepless) you can spend hours on the material posted--and all feedback is welcome.

About the speaker:

Following a dual career as a professor at the Univeristy of California, Berkeley and as a practicing architect, Christopher Alexander is now taking his ideas and activities "on-line" through a new website He is most well known among computer scientists for the book A Pattern Language published in the late 70's. His new work The Nature of Order is now at the printer and will soon be available.

Contact information:

Christopher Alexander