| Vocabulary knowledge is a critical aspect to an individual's ability to read, communicate, and acquire new knowledge. Deficits in vocabulary knowledge, which may appear as early as one year of age, are long-lasting and are associated with a number of negative academic outcomes (e.g., Biemiller & Slonim, 2001; Beitchman, Jiang, Koyama, Johnson, Escobar, Atkinson, Brownlie, & Vida, 2008.; Pearson, Hiebert, & Kamil, 2007). Understanding the developmental trajectory of vocabulary acquisition may permit early, targeted intervention to reduce or prevent costly vocabulary deficits. Current work on vocabulary acquisition calls for better understanding of what words children know, when children will learn certain words, and how well those words will be known. Biemiller and Slonim's work (2001) laid promising groundwork for answering such question in their examination of root word vocabulary knowledge and the evidence for sequential order in word acquisition in children grades K-6. The current study sought to explore the depth and breadth of preschool vocabulary knowledge by extending the work of Biemiller and Slonim to a non-reading preschool sample. Preschool children ages 3-5 were evaluated using the newly developed Preschool Assessment of Vocabulary: Expressive and Receptive (PAVER); this measure is unique in that it tests the same vocabulary word in both the expressive and receptive format. The findings of the study indicate that expressive and receptive approaches to vocabulary assessment are not interchangeable; both approaches were significantly associated with children's emergent literacy skill. |
