Rouse presents this as a report on procedure rather than on findings. The material comes from the Fort Liberte region of northern Haiti, already excavated and sorted; the question is how to turn artifacts into history.

The method rests on two units. A type is the set of attributes shared by a class of objects, treated as an abstract pattern rather than as the objects themselves. A mode is a single attribute -- a design, a technique, a property such as hardness -- handled on its own as a culture trait equal in standing to a type. Types are reached by classification, modes by analysis.

Both are traced from site to site and, once a time scale is built from the shifting frequencies of eight selected modes, from period to period. Diffusion, persistence and replacement then read those distributions as events. Culture, Rouse insists, lies in the standards guiding the artisan, not in the objects.