ITERIM is an IBM System/360 FORTRAN IV(H) program designed primarily to assess and improve classifications, although it can be used also for principal component analysis, discriminant analysis, and one-way multivariate analysis of variance. Three criteria, pooled within-groups sum of squares, Wilks' Lambda, and the sum of the eigen values associated with discriminant functions, are computed to assess and compare classifications. The improvement of a classification is achieved through reduction of pooled within-groups sum of squares in the discriminant space. The classifications compared must contain the same number of items, the same number of groups, and must be defined relative to the same number of variables. A number of options, both as to computations and output, are provided.