Two sociometric techniques were used in Project PRIME (Programmed Re-Entry Into Mainstream Education) to elicit data from peers about the behavior of selected normal and handicapped children in each of the 500 plus classrooms studied. One of these instruments was called Guess Who. The Guess Who instrument consists of 29 questions, such as, "Who is friendly to everyone?" Each child in the class writes the name of one classmate in response to each question. The names were encoded as identification numbers onto optical scanning sheets, which were then transfered to magnetic tape. Initial compilation of frequencies of nomination was carried out for 13,000 pupils. Four clear factors were obtained from analysis of 29 nomination sociometric items. Reliability estimates for the four factor scales are moderate, but adequate for comparison of groups. Educable Mentally Retarded (EMR) and Learning Disabled (LD) are perceived to have a definite cognitive deficit, and to be more disruptive in their behavior than normal peers. A pupil clustering technique yielded a stable seven group result. (Author/DEP)