In two-level designs, the total sample is a function of both the number of Level 2 clusters and the average number of Level 1 units per cluster. Traditional multilevel power calculations rely on either the arithmetic average or the harmonic mean when estimating the average number of Level 1 units across clusters of unbalanced size. The current…

Power in multilevel models remains an area of interest to both methodologists and substantive researchers. In two-level designs, the total sample is a function of both the number of level-2 (e.g., schools) clusters and the average number of level-1 (e.g., classrooms) units per cluster. Traditional multilevel power calculations rely on either the…

This study explored heterogeneity in literacy development among 2,300 Hispanic children receiving English as a Second Language (ESL) services at the start of kindergarten. Two research questions guided this work: (1) Do Spanish-speaking English language learners receiving ESL services in the fall of kindergarten demonstrate homogeneous early…

The purpose of this study was to explore patterns of within-group variability in the emergent literacy skills of preschoolers who are at risk for academic difficulties. We used the person-centered approach of cluster analysis to identify profiles of emergent literacy skills, taking into account both oral language and code-related skills.…

The purpose of this study was to identify subgroups of adult basic education (ABE) learners with different profiles of skills in the core reading components of decoding, word recognition, spelling, fluency, and comprehension. The analysis uses factor scores of those 5 reading components from on a prior investigation of the reliability and…

Vocabulary knowledge at school entry is a robust predictor of later reading achievement. Many children begin formal reading instruction at a significant disadvantage due to low levels of vocabulary. Until recently, relatively few research studies examined the efficacy of vocabulary interventions for children in the early primary grades (e.g.,…

Research Findings: Recent evidence suggests that children benefit from pre-K programs in terms of both academic and social skills and that this growth is predicted by the quality of the interactions teachers have with students. Prior cluster analysis revealed 5 distinct quality profiles of teacher-child interactions in pre-kindergarten based on…

Compares various base-rate procedures with statistical-significance testing approach used by psychologists. Nonlinear multivariate method is used to determine whether children with a learning disability or emotional disturbance are more likely to show unusual subtest patterns than are children from the normative sample of Wechsler Intelligence…

School readiness assessment is a prominent feature of early childhood education. Because the construct of readiness is multifaceted, we examined children's patterns on multiple indicators previously found to be both theoretically and empirically linked to school readiness: social skill, interactions with parents, problem behavior, and performance…