There is no doubt that culture changes. All around us are artifacts that change at least as rapidly as last season's TV listings. One amusing example is provided by the range of "Darwin's Fish" that have appeared on bumper stickers, and then mutated to fit different social niches.
We are especially interested in assessing change in scientific culture. Few social activitees have left such a careful historical record. Further, the scientific record captures the dynamic connecting both an individual scientist's cognitive activities and the integration of these activities as part of the larger social process. That is, each publication captures current thinking of individuals and small groups, while a full published record spanning decades can reflect a ``community consensus'' of conflict, agreement and ultimately new, shared knowledge. Further, the fact that more and more scientific communication occur as the via electronic artifacts means that the analysis of change can proceed within firm empirical foundations.