Time-sampling analysis of infants' natural language environments in the home.
D002657:Child Development; D005260:Female; D006801:Humans; D007223:Infant; D007802:Language; D007804:Language Development; D008297:Male; D010287:Parent-Child Relations; D012931:Social Environment; D013060:Speech; D013637:Tape Recording; D014705:Verbal Behavior