An ethnographic study assessed the family constellations of ninth graders in an urban public school through cluster analysis. Survey data were collected from a random sample of 120 high school freshmen and were used to compute 4 variables for each student: (1) presence of the mother in the home; (2) presence of the father in the home; (3) presence of other adults in the home; and (4) presence of other children in the home. The familial configurations of subjects were extended maternal (n=7), nuclear family (n=26), mother with children (n=46), orphaned (n=13), only child (n=21), and adopted (n=7). Family constellation, determined by cluster analysis, and gender served as independent variables in a general linear model used to assess student attendance at school and grade point average. Results indicate that the educational performance of males and females differs with respect to the types of familial configurations in which they find themselves. Females appear to perform most poorly in family units characterized by mother's presence and father's absence, but males perform best in groups where the mother and/or maternal relations were present. Contrary to expectations, males in this group of students perform best when the father is absent from the family configuration. This ethnographic approach appears promising for revising familial configuration effects within heterogeneous and transient populations. Two tables present study data. (SLD)