THE 99 CHILDREN IN THIS STUDY WERE 3 YEARS OF AGE OR YOUNGER. THIS AGE GROUP WAS STUDIED BECAUSE PRELIMINARY ANALYSIS OF EXISTING DATA SHOWED THAT FAMILIES IN WHICH THE ABUSED CHILD WAS LESS THAN 3 YEARS OLD DIFFERED FROM FAMILIES IN WHICH THE CHILD WAS OLDER. THE RESULTS OF THE DETAILED STUDY WERE APPLIED TO AN EXPERIMENTAL HOSPITAL PROGRAM FOR ABUSED CHILDREN WITHIN THIS AGE GROUP. DATA WERE COLLECTED WITH A PRECODED SURVEY QUESTIONNAIRE COMPLETED BY SOCIAL WORKERS WORKING WITH THE STUDY FAMILIES. DATA ON 251 VARIABLES (GROUPED INTO NINE CATEGORIES) WERE ANALYZED USING A CLUSTER ANALYSIS METHOD KNOWN AS HIERARCHICAL NEAREST-NEIGHBOR CLUSTERING. FOUR CLUSTERS OF FAMILIES WERE ESTABLISHED. ABUSE IN THE FIRST CLUSTER APPEARS TO BE THE RESULT OF SEVERE INDIVIDUAL PSYCHOPATHOLOGY AND OR INTERPERSONAL CONFLICT REQUIRING PSYCHOTHERAPY. FAMILIES IN THE SECOND CLUSTER APPEAR TO BE LESS IN CONFLICT IN THEIR RELATIONSHIP TO CHILDREN AND WOULD BENEFIT MOST FROM PRACTICAL CHILD-REARING ADVICE. THE PRIMARY PRECIPITATING FACTOR OF ABUSE IN THE THIRD GROUP IS ECONOMIC STRESS WHICH MAKES SUCH FATHERS VULNERABLE AND UNDERMINES THEIR SELF-CONFIDENCE. SUCH PARENTS WOULD BENEFIT FROM THE TRAINING GIVEN PARENTS IN THE SECOND CLUSTER. PARENTS IN THE FOURTH CLUSTER WOULD BENEFIT FROM PSYCHOTHERAPY BUT THEIR FEELINGS OF WORTHLESSNESS AND INADEQUACY MAKES SUCH TREATMENT DIFFICULT. EVEN THOUGH SUCH CLASSIFICATIONS CAN AID IN DEVELOPING MORE EFFECTIVE TREATMENT PROCEDURES AND SOCIAL POLICIES, ADDITIONAL RESEARCH INTO THE ETIOLOGY OF CHILD ABUSE IS NEEDED. REFERENCES, CHARTS, AND TABLES ARE PROVIDED. (KCP)