Effects of a Tier 2 vocabulary intervention on the word knowledge of kindergarten students at-risk for language and literary difficulties

This dissertation study examined the effectiveness of a Tier 2 vocabulary intervention, in addition to research-based Tier 1 vocabulary instruction, implemented with students at-risk for language and learning difficulties. Participants included 43 kindergarten students enrolled in an urban elementary school in the Northeast. All participants received research-based, Tier 1 instruction delivered in the classroom setting. Students with the 20 lowest scores (i.e., standard scores \u3c 92) on the Peabody Picture Vocabulary Test-III (PPVT-III) received small group, Tier 2 vocabulary intervention in addition to the Tier 1 vocabulary instruction. All students listened to two readings of two storybooks that each contained four target vocabulary words. Students identified as at-risk received Tier 1 instruction plus additional Tier 2 intervention on two target words from each story and only Tier 1 instruction on the remaining 2 target words from each story. Words receiving Tier 2 intervention were counterbalanced across groups. Target word knowledge was assessed using experimenter developed measures of receptive and expressive knowledge that were administered one week following the intervention and again seven weeks later. Results were analyzed using repeated measures ANOVAs that contained two within-subjects factors: classroom-based Tier 1 instruction versus classroom-based Tier 1 instruction plus additional Tier 2 intervention, and posttest versus delayed posttest. Additionally, descriptive statistics comparing word knowledge of students identified as being at-risk and students who were not identified as being at-risk were examined. Overall, findings indicated that at-risk students made greater gains in word knowledge on target words that received the additional Tier 2 intervention as compared to words that received only classroom-based instruction. Furthermore, descriptive statistics indicated that at-risk students\u27 scores on words receiving Tier 2 intervention were similar to scores of students who were not identified as being at-risk and received only Tier 1 instruction. Implications are discussed in relations to the importance of early vocabulary intervention and early identification of students who may be at-risk for language and learning difficulties. Limitations of the current study and directions for future research are also explored.