THE WAYS LANGUAGE IS USED BY CHILDREN IN VARIOUS SUBCULTURE GROUPS WERE INVESTIGATED, AND AN EVALUATION WAS MADE OF WHETHER OR NOT THE LANGUAGE OF ANY GROUP CAN BE CONSIDERED DEFICIENT BY USE OF SOME CRITERIA. THE AUTHOR EVALUATED RESEARCH IN LINGUISTICS, DEVELOPMENTAL PSYCHOLOGY, SOCIOLOGY, AND ANTHROPOLOGY DONE WITH CHILDREN OF DIFFERENT SOCIAL CLASSES AND MINORITY GROUPS. METHODS OF DESCRIBING NONSTANDARD ENGLISH IN TERMS OF ERRORS, CONTRAST, AND TRANSFORMATIONAL GRAMMAR WERE PRESENTED. THE AUTHOR STATED THAT BOTH SOCIAL AND PSYCHOLOGICAL CRITERIA ON THE DEFICIENCY OF NONSTANDARD ENGLISH EXISTS, BUT THAT THERE IS MORE EVIDENCE ON SOCIAL GROUNDS. HE OUTLINED SUCH MEDIATIONAL VARIABLES AS SOCIAL CLASS WHICH AFFECT LANGUAGE DEVELOPMENT. HE STATED THAT PHONOLOGY AND SENTENCE STRUCTURE MAY OBSCURE SUCH MEDIATORS AS THE NONVERBAL CONTEXT (WHICH INCLUDES AFFECTIVE QUALITY AND WHETHER THE CHILD TALKS TO ADULTS OR CHILDREN), AND THAT LANGUAGE STIMULATION MAY VARY IN QUALITY AND QUANTITY. THE PROBLEMS WHICH DIALECT DIFFERENCES POSE FOR LANGUAGE DEVELOPMENT SCALES WERE PROBED. THE AUTHOR SUGGESTED A CHILD'S LANGUAGE DEVELOPMENT BE EVALUATED FOR PROGRESS TOWARD THE NORMS OF HIS PARTICULAR SPEECH COMMUNITY. INTERINDIVIDUAL AND INTRAINDIVIDUAL MODES OF COMMUNICATION WERE PRESENTED. THE IMPORTANCE OF THE RELATIONSHIP BETWEEN THESE TWO MODES TO STUDIES OF SUBCULTURAL DIFFERENCES IN CHILD LANGUAGE WAS STRESSED. THIS ARTICLE IS A REPRINT FROM "MERRILL-PALMER QUARTERLY OF BEHAVIOR AND DEVELOPMENT," VOLUME 12, NUMBER 3, 1966. (TC)