This describes a marital relationship in which the partners share a category, from the possible options, of one variable, such as birthplace, level of education, etc. For example, both are from the same municipality, both have university degrees, etc.

In the table formed by the same variable for the both partners, the homogamous marriages are those located on the diagonal of the table. Other marriages are classified as hetrogamous.

In some homogamy tables the number of expected homogamous couples for a variable has been calculated. In this section the number of homogamous married couples that would have been produced by a random distribution is included.