1. n. a relative position along an ordered continuum. See rank order.

2. vb. to arrange items in a graded order, such as from highest to lowest value. In a peer nomination study, for example, a child might be asked to order individuals in a class from most disruptive to least disruptive. See also ordinal data.

3. n. the maximum number of linearly independent row vectors or column vectors in a correlation matrix: These values are always equal. For example, a 10 × 10 correlation matrix of personality scores might have a rank of 6, indicating that there are not 10 independent pieces of information present in the 10 scores.