A two-step sampling weight approach to growth mixture modeling for emergent and developing skills with distributional changes over time.

Emergent reading skills are crucial to the development of fluency and comprehension, and as such, assessing kindergarten entry skills is critical to inform educational decisions. However, skills that are assessed too early are likely to yield many zero scores, as most students do not yet have the experience or ability to perform the task. Although these floor effects typically lessen across time to show near-normal distributions, growth models cannot accommodate repeated measures with different distributions. The purposes of this paper are to (a) introduce a two-step sampling weight approach to growth mixture modeling that addresses distributions changing over time, and (b) apply the approach to a sample of 1911 kindergarten students universally screened on an emergent reading skill (letter sound fluency) across the year. Results distinguish between students that begin at zero and make meaningful gains and those who begin at zero and do not. We discuss the methodological implications of our approach and the practical implications for growth modeling and early identification.

Growth and gaps in mathematics achievement of students with and without disabilities on a statewide achievement test.

This study estimated mathematics achievement growth trajectories in a statewide sample of 92,045 students with and without disabilities over Grades 3 to 7. Students with disabilities (SWDs) were identified in seven exceptionality categories. Students without disabilities (SWoDs) were categorized as General Education (GE) or Academically/Intellectually Gifted (AIG). Students in all groups showed significant growth that decelerated over grades as well as significant variability in achievement by student group, both at the initial assessment in Grade 3 and in rates of growth over time. Race/ethnicity, gender, parental education, free/reduced lunch status, and English language proficiency were also significant predictors of achievement. Effect size estimates showed substantial year-to-year growth that decreased over grades. Sizeable achievement gaps that were relatively stable over grades were observed between SWoDs and students in specific exceptionality categories. Our study also demonstrated the importance of statistically controlling for variation related to student demographic characteristics. Additional research is needed that expands on these results with the same and additional exceptionality groups.

In search of average growth: describing within-year oral reading fluency growth across Grades 1-8.

Measures of oral reading fluency (ORF) are perhaps the most often used assessment to monitor student progress as part of a response to intervention (RTI) model. Rates of growth in research and aim lines in practice are used to characterize student growth; in either case, growth is generally defined as linear, increasing at a constant rate. Recent research suggests ORF growth follows a nonlinear trajectory, but limitations related to the datasets used in such studies, composed of only three testing occasions, curtails their ability to examine the true functional form of ORF growth. The purpose of this study was to model within-year ORF growth using up to eight testing occasions for 1448 students in Grades 1 to 8 to assess (a) the average growth trajectory for within-year ORF growth, (b) whether students vary significantly in within-year ORF growth, and (c) the extent to which findings are consistent across grades. Results demonstrated that for Grades 1 to 7, a quadratic growth model fit better than either linear or cubic growth models, and for Grade 8, there was no substantial, stable growth. Findings suggest that the expectation for linear growth currently used in practice may be unrealistic.

Writing performance assessments: how important is extended time?

Students in Grades 5 and 8 completed a 30-minute writing performance assessment and a writing performance assessment completed over 3 days. Assessments were evaluated on four traits (ideas, organization, conventions, and sentence fluency). A significant interaction was found at Grade 5 between length of time allotted for the assessment and students' educational classification (general or special education). Grade 5 students performed significantly better on the 3-day writing assessment, with students in special education benefiting the most. At Grade 8, there were no differences between scores on the 30-minute and the 3-day assessments. No significant differences were found in students' writing performance across various types of discourse (narrative, imaginative, persuasive, and expository); significant differences were reported across certain writing traits. We shared three hypotheses for reported differences: (a) students' proficiency with the writing process, (b) scoring scale bias, and (c) differences in the revision behaviors of developing and mature writers. Educational implications related to statewide test programs are discussed.