The CSBS is intended to generate profiles of strengths and weaknesses for a child across communicative, social-affective, and symbolic domains of development for use in diagnostic assessment and intervention planning. Because of the well documented variability in normal development of language, the sensitivity to different rates of growth in children is an important part of the CSBS. In order for abnormal variability to be detected, normal variability must be sufficiently handled by the conversion of raw scores to standard scores. Goodwyn (1995) examined the variability of CSBS standard scores over time in a small sample of normally developing infants using generalizability theory (Cronbach, Gleser, Nanda, & Rajaratnam, 1972). Generally, her findings indicated sensitivity of the instrument to varying rates of development across children, sensitivity to changes in children's abilities over time, and proper functioning of the normed scores.

The relatively small sample size (N = 282) used in the development of the instrument's norms is an aspect of the CSBS that could be cause for concern. Yet, Goodwyn (1995) found no evidence for improper functioning of the norms.

Some limitations regarding the administration and scoring of the instrument are worth noting. We found a significant disparity in the estimated and actual time required to score the videotaped samples. Even after training and experience with the instrument, we found that scoring took a minimum of one hour and forty-five minutes. Although we have not reveiwed the Scoring Tutorial tapes, it is likely that they will be helpful due to the complexity of the scoring. Applied Symbolix is scheduled to release the CSBS Quick Score in the near future. The Quick Score is designed to reduce the complexity of recording and scoring the instrument.

A reordering of the testing procedure during the Language Comprehension portion may be advisable. As the objective is to assess the child's linguistic comprehension, we suggest measuring this while the child is initially focused on the doll prior to presenting the toy sets in the Symbolic Play Probes section of the testing procedure. We have found during testing, that once children have been presented with the toy sets in the Symbolic Play Probes section, they are reluctant to go back to focus only on the doll to identify body parts in the Language Comprehension Probes section. Reordering the testing procedure in this way may cause the norms for the symbolic cluster scale and communication composite score to change slightly.

Increased awareness of the need for early detection and intervention of disorders in children was underscored by the inclusion of children under the age of five in the Individuals with Disabilities Education Act. The CSBS has potential to be a useful tool for early identification and intervention planning of language and communication disorders for this age group. The standardized behavior sampling used in the CSBS is unique; with further development, the CSBS may become the instrument of choice for assessing communication and symbolic abilities in very young children.