Criteria for Determining Whether Certain Categories in a Cross-Classification Table Should Be Combined, with Special Reference to Occupational Categories in an Occupational Mobility Table

This article considers two kinds of criteria for determining whether certain rows in a two-way cross-classification table should be combined and/or whether certain columns in the table should be combined. These criteria pertain to homogeneity and structure. When these criteria are applied to the classic cross-classification on British occupational mobility recently studied by Duncan, Goodman, Hauser, and Clogg, new insights into these data are obtained. The application of these criteria in the present article also helps to clarify the meaning of the criteria considered here and related terms recently discussed by Breiger.