Representational Ability as a Predictor of Later Expressive Vocabulary

Fifty eight toddlers (17-34 months) with developmental delays participated in a 12 month longitudinal study to test the predic tive relationship between prelinguistic representational ability and later expressive vocabulary. Two representational abilities were examined, vocabulary comprehension and level of representational play. The MacArthur Communicative Developmental Inventory/Infants (Fenson et al., 1991) was used to measure vocabulary comprehension and a play scale adapted from McCune (1995) was used to establish level of representational play. Expressive vocabulary was measured one year later in a set of structured interactions with a familiar adult using the Communication Composite of the Communication and Symbolic Behavior Scales (Wetherby & Prizant, 1993). The results indicated that level of representa tional play was a significant predictor of later expressive vocabulary but vocabulary comprehension was not.