The authors focus on developing standardized measures for models of structure in interpersonal relations. A theorem is presented which yields expectations and variances for measures based on triads. Random models for these measures are discussed and the procedure is carried out for a model of a partial order. This model contains as special cases a number of previously suggested models, including the structural balance model of Cartwright and Harary, Davis's clustering model, and the ranked-clusters model of Davis and Leinhardt. In an illustrative exmaple, eight sociograms are analyzed and the general model is compared with the special case of ranked clusters.