The purpose of this paper is to report on the development and validation of the Social Problem Situation Analysis Measure (SPSAM), a measure of the ways in which children understand and attempt to resolve problematic social situations. The SPSAM is an assessment procedure in which children are shown cards depicting sequences of unfolding action in peer- and teacher-related problematic situations. Reactions of second grade children to these situations are examined in terms of their understanding of situations and characters, consideration of possibilities, specificity of planning, expectancies, and behavioral strategies for resolution. Sections of this paper contain a description of the SPSAM and its scoring system, the initial validation design used, replicated findings concerning the organization of social problem solving cognitions in young children, external validation data, and a discussion of implications for future research. External validation studies revealed significant relationships of SPSAM variables to sociometric and teacher rating scores. Internal validation analyses showed consistent patterns of SPSAM variables over time and test conditions. (Author/RH)