A parent report instrument for early language assessment

Abstract

A structured questionnaire for evaluating the level of communicative and linguistic development at 12, 16 and 20 months of age respectively was administered to the parents of 23 children for three different assessments. For a subsample of 14 subjects the questionnaire was filled in by the parents and by a trained observer in a two-hour observational session at home. The aim of the study was two-fold: (a) to verify the validity of the instrument and specifically its predictive validity; (b) to verify the reliability of the information given by parents through a direct comparison between the data in the questionnaire filled in by the parents and the data in the same questionnaire filled in by the observer. Results show that, on the basis of measures reported at 12 months, the instrument can predict linguistic development at 20 months as evaluated by means of a Vocabulary Checklist. Furthermore, the pattern of communicative and linguistic development reported by parents is consistent with that reported by the observer. Finally, the sample's lexical development exhibits a wide range of individual variation, with lexicons consisting of about 8 to 628 different words at 20 months of age.