In a number of publications, (i, 2, 3, 4), the Fels Parent Behavior Scales have been presented as a technique for the appraisal of one aspect of the home environment of children. The battery comprises 30 scales on which each child in the research program of the Fels Research Institute is periodically appraised. The research on parent behavior has heretofore been concerned chiefly with the interpretation of the profile of 30 ratings, and the psychological meaning of various patterns of ratings. Such research is, however, only preliminary. In a longitudinal study such as that undertaken by the Fels Institute, the scales are employed as a tool for the understanding of the development of individual children. It is not sufficient merely to appraise each home once. In addition, each home must be periodically studied and the changes in parent behavior must be related to the personality of the child in that home.