Which words to teach? Unpacking results from an effective vocabulary intervention for children with SLI

• In Event: The Reduction of Differences in Early Vocabulary

Abstract

Objectives
Early vocabulary skills support success in reading and beyond (Duncan et al., 2007), including for preschoolers with or at risk for specific language impairment (SLI) (Grigorenko et al., 2020). However, few early vocabulary interventions have increased children’s vocabulary knowledge (Landry et al., 2009; Neuman & Kaefer, 2018; Wasik et al., 2016). One pathway forward involves closely examining what words children in successful interventions are most likely to know as they begin preschool, and what words they learn through the intervention.
Theoretical Framework
One strategy for choosing words (Beck et al., 2013) involves categorizing words into three tiers: Tier 1 (everyday words, such as circle), Tier 2 (academic terms with utility across fields such as sphere), and Tier 3 (highly specialized terms such as geodome). Researchers generally suggest focusing on Tier 2 words, but preschoolers – particularly those with or at risk for SLI – may have meaningful gaps in their knowledge that warrant focus on some Tier 1 words as well.
Current Study
This secondary analysis of a recent RCT (Authors, in review) of our vocabulary intervention (Authors, 2023) in inclusive settings, in which intervention children outperformed business-as-usual peers on a taught-word measure (d=0.28; see Authors, in review), pursues two aims:
Aim 1: What Tier 1 and 2 words do preschoolers with or at risk for SLI in these inclusive classrooms know at the beginning of preschool?
Aim 2: After one academic year of our model, how does children’s word knowledge change?
Method
Participants. Participants were in 22 preschoolers (50% male) in five inclusive private preschool classrooms identified as with or at risk for SLI and received family consent for assessment.
Intervention. For the year-long intervention, teachers received materials targeting 10 words per week, as well as PD sessions and coaching to help them use the materials.
Data source. A project-aligned vocabulary measure with 10 items randomly selected from 300 target words was administered to each child in fall (pretest) and spring (posttest). Words spanned Tier 1 (50%) and Tier 2 (50%). Items were first presented expressively, as assessors showed a picture of the word and asked, “What’s this?” For missed items, assessors showed a receptive plate with that word and three foils and asked, “Show me [word].” Children received 1 point for correct expressive answers, 1/2 point correct receptive answers, and 0 points for incorrect responses.
Results
Aim 1: As in Table 1, fewer than 30% of children offered a correct, expressive response for any Tier 1 words at pre-test, and fewer than 10% of children offered correct, expressive responses for Tier 2 words.
Aim 2: Children made significant (p<.05) gains on three Tier 1 words, but 30% still offered incorrect responses on two (trash truck, helmet). At Tier 2, only two words showed marginal gains (p=0.085 for scaffold and soil). Correct, expressive responses were rare.
Scientific & Scholarly Significance
For children at risk for or diagnosed with SLI, there may be value in focusing on both Tier 1 and Tier 2 words in early vocabulary interventions in inclusive settings.

Authors

• Barbara Wasik, Temple University

• Annemarie Hindman, University of North Carolina - Chapel Hill