Nancy Scammacca

Mathematics Intervention for First- and Second-Grade Students With Mathematics Difficulties The Effects of Tier 2 Intervention Delivered as Booster Lessons

This study sought to examine the effects of Tier 2 intervention in a multitiered model on the performance of first- and second-grade students who were identified as having mathematics difficulties. A regression discontinuity design was utilized. Participants included 126 (Tier 2, n = 26) first graders and 140 (Tier 2, n = 25) second graders. Tier 2 students received 15-min intervention booster lessons for 18 weeks in early mathematics skills and concepts. Results showed a significant intervention effect for second-grade Tier 2 students on the Texas Early Mathematics Inventories—Progress Monitoring (TEMI-PM) total standard score. The effect was not significant for first-grade Tier 2 students.

Extensive Reading Interventions for Students With Reading Difficulties After Grade 3

This synthesis extends a report of research on extensive interventions in kindergarten through third grade (Wanzek & Vaughn, 2007) to students in Grades 4 through 12, recognizing that many of the same questions about the effectiveness of reading interventions with younger students are important to address with older students, including (a) how effective are extensive interventions in improving reading outcomes for older students with reading difficulties or disabilities and (b) what features of extensive interventions (e.g., group size, duration, grade level) are associated with improved outcomes. Nineteen studies were synthesized. Ten studies met criteria for a meta-analysis, reporting on 22 distinct treatment/comparison differences. Mean effect sizes ranged from 0.10 to 0.16 for comprehension, word reading, word reading fluency, reading fluency, and spelling outcomes. No significant differences in student outcomes were noted among studies related to instructional group size, relative number of hours of intervention, or grade level of intervention.

A Meta-Analysis of Interventions for Struggling Readers in Grades 4–12 1980–2011

This meta-analysis synthesizes the literature on interventions for struggling readers in Grades 4 through 12 published between 1980 and 2011. It updates Scammacca et al.’s analysis of studies published between 1980 and 2004. The combined corpus of 82 study-wise effect sizes was meta-analyzed to determine (a) the overall effectiveness of reading interventions studied over the past 30 years, (b) how the magnitude of the effect varies based on student, intervention, and research design characteristics, and (c) what differences in effectiveness exist between more recent interventions and older ones. The analysis yielded a mean effect of 0.49, considerably smaller than the 0.95 mean effect reported in 2007. The mean effect for standardized measures was 0.21, also much smaller than the 0.42 mean effect reported in 2007. The mean effects for reading comprehension measures were similarly diminished. Results indicated that the mean effects for the 1980–2004 and 2005–2011 groups of studies were different to a statistically significant degree. The decline in effect sizes over time is attributed at least in part to increased use of standardized measures, more rigorous and complex research designs, differences in participant characteristics, and improvements in the school’s “business-as-usual” instruction that often serves as the comparison condition in intervention studies.

Meta-Analysis With Complex Research Designs: Dealing With Dependence From Multiple Measures and Multiple Group Comparisons

Previous research has shown that treating dependent effect sizes as independent inflates the variance of the mean effect size and introduces bias by giving studies with more effect sizes more weight in the meta-analysis. This article summarizes the different approaches to handling dependence that have been advocated by methodologists, some of which are more feasible to implement with education research studies than others. A case study using effect sizes from a recent meta-analysis of reading interventions is presented to compare the results obtained from different approaches to dealing with dependence. Overall, mean effect sizes and variance estimates were found to be similar, but estimates of indexes of heterogeneity varied. Meta-analysts are advised to explore the effect of the method of handling dependence on the heterogeneity estimates before conducting moderator analyses and to choose the approach to dependence that is best suited to their research question and their data set.

A Century of Progress: Reading Interventions for Students in Grades 4–12, 1914–2014

The history of research on interventions for struggling readers in Grades 4 through 12 dates back to 19th-century case studies of seemingly intelligent children who were unable to learn to read. Physicians, psychologists, educators, and others were determined to help them. In the process, they launched a century of research on a wide variety of approaches to reading intervention. As shown in this systematic narrative review, much has changed over time in the conceptualization of reading interventions and the methods used to determine their efficacy in improving outcomes for struggling readers. Building on the knowledge gathered over the past 100 years, researchers and practitioners are well-poised to continue to make progress in developing and testing reading interventions over the next 100 years.

Benchmarks for Expected Annual Academic Growth for Students in the Bottom Quartile of the Normative Distribution

Effect sizes are commonly reported for the results of educational interventions. However, researchers struggle with interpreting their magnitude in a way that transcends generic guidelines. Effect sizes can be interpreted in a meaningful context by benchmarking them against typical growth for students in the normative distribution. Such benchmarks are not currently available for students in the bottom quartile. This report remedies this by providing a comparative context for interventions involving these students. Annual growth effect sizes for K–12 students were computed from nationally normed assessments and a longitudinal study of students in special education. They reveal declining growth over time, especially for reading and math. These results allow researchers to better interpret the effects of their interventions and help practitioners by quantifying typical growth for struggling students. More longitudinal research is needed to show growth trajectories for students in the bottom quartile.

Current Evidence on the Effects of Intensive Early Reading Interventions

Many students at risk for or identified with reading disabilities need intensive reading interventions. This meta-analysis provides an update to the Wanzek and Vaughn synthesis on intensive early reading interventions. Effects from 25 reading intervention studies are analyzed to examine the overall effect of intensive early reading interventions as well as relationships between intervention and student characteristics related to outcomes. The weighted mean effect size (ES) estimate (ES = 0.39), with a mean effect size adjusted for publication bias (ES = 0.28), both significantly different from zero, suggested intensive early reading interventions resulted in positive outcomes for early struggling readers in kindergarten through third grades. There was no statistically significant or meaningful heterogeneity in the study-wise effect sizes. Exploratory examination of time in intervention, instructional group size, initial reading achievement, and date of publication are provided.

The Effect of a Social Studies-Based Reading Intervention on the Academic Vocabulary Knowledge of Below-Average Readers.

ABSTRACT Deficits in academic vocabulary knowledge plague students who struggle with reading and impact their reading comprehension and performance in content area courses. Experts have developed interventions aimed at improving vocabulary instruction. However, questions remain concerning the effects of vocabulary gains on reading comprehension and content learning. To address these questions, we explored the impact of an intervention on social studies academic vocabulary knowledge among 8th-grade students with below-average reading comprehension. Results of a randomized controlled trial indicated that treated students had greater mastery of social studies vocabulary. In addition, scores on vocabulary knowledge predicted content acquisition and reading comprehension scores. These results underscore the need for in-depth vocabulary instruction and the importance of assessing gains in word knowledge in terms of both breadth and depth.

Causal Mediation in Educational Intervention Studies

Understanding the factors that mediate the effect of educational or behavioral intervention is critical to advancing both research and practice. When properly implemented, mediators add depth to the results of intervention research, indicating why a program works, highlighting ways to enhance its effectiveness, and revealing the elements that are essential to successful implementation. However, many researchers find mediation a difficult topic and struggle to implement it properly in statistical models of effects from between-groups randomized studies. In an effort to bring clarity to the topic of mediation and encourage its use where appropriate, this article lays out the requirements for evidence of a causal-mediated effect. An example of a randomized trial of an intervention targeting self-regulation and student behavior is used to illustrate the process of conceptualizing and testing for mediation of treatment effects. Statistical considerations also are addressed.