A study was conducted to investigate parental belief systems and parental childrearing practices relative to the intellectual development of their communication-handicapped preschool children. Consideration was given to the context of family size and ordinal position of the communication-handicapped child. A total of 60 two-parent families with communication-handicapped preschoolers composed the experimental group; 60 families without communication-handicapped children participated as the control group. Three classes of assessment instruments were used to collect data from each family: (1) parent questionnaires and interviews, (2) child assessments and screening tests, and (3) observations of parent/child interactions. It was hypothesized that parental practices would be directly related to parents' beliefs about child development processes and about their own child's cognitive competence. In general, results provided only partial support for this hypothesis. (Related materials, including data tables and descriptions of the administration and coding of measurement instruments, are appended.) (MP)