Contingency table
A table presenting a cross-classification of categorical data such that the categories of one characteristic are indicated horizontally (in rows) and the categories of another characteristic are indicated vertically (in columns).
Note: Each cell of the table will indicate the number or proportion of individuals who have both the characteristic on its row and in its column. The simplest contingency table is the fourfold, or 2x2 table, which is used in clinical trials, for example, to compare dichotomous outcomes for two groups.