Early Formative Period of Coastal Ecuador: the Valdivia and Machalilla Phases

...The principal subdivision we have made is between decorated and undecorated surfaces. Although this is an obvious basis for distinction, it is one that is often not made in ceramic classification. Failure to separate decorated from undecorated sherds is usually justified on the ground that it prevents sherds from a vessel decorated on only part of the surface from being divided between two pottery types. This argument can be ignored, however, if the purpose of the classification is to deal with the multitude of sherds recovered from habitation refuse and to show change through time. Failure to separate decorated from undecorated sherds has a serious disadvantage in that it makes it difficult or impossible to ascertain the exact proportion of the pottery that was decorated, or the frequency of certain kinds of decoration at any particular point in time, both of which can be used as a basis for inferences about level of competence in ceramic technology, which in turn provides clues to level of sociopolitical organization (Meggers and Evans, 1958). This, in our view, is an advantage outweighing the strictly puristic superiority of a classification that attempts to deal with complete vessels...