This blog post is part of our Research Article of the Month series. For this month—Dyslexia Awareness Month—we highlight “Forty Years of Reading Intervention Research for Elementary Students with or at Risk for Dyslexia: A Systematic Review and Meta-Analysis” by Hall et al. (2023).
Find more information on terminology specific to literacy learning in our reading glossary. Important words related to research are bolded throughout this post, and definitions of these terms are included at the end of the article in the “Terms to Know” section.
Key Takeaways
- Students with or at risk for dyslexia benefit from reading interventions that include instruction in foundational reading skills.
- Students with or at risk for dyslexia tend to make somewhat greater reading gains when they receive more intensive intervention. This suggests that increasing the dosage may help accelerate reading growth for students with or at risk for dyslexia.
- Small-group and one-on-one interventions produced similar effects on reading outcomes; instructional group size did not meaningfully moderate intervention effects.
What Did the Researchers Examine?
Hall et al. (2023) conducted a meta-analysis to estimate the mean effect of reading interventions that include instruction in foundational skills on reading outcomes for elementary students with or at risk for dyslexia. In this study, foundational skills included phonological awareness, phonics, word reading, spelling, and text reading fluency with instruction also addressing word meaning and reading comprehension. The researchers also examined whether student, intervention, outcome, and study characteristics helped explain differences in intervention effects.
What Did the Researchers Find?
Results indicated that the interventions had a positive effect on students’ reading outcomes. However, the size of the effects varied across studies. The researchers looked at several factors that might explain those differences, such as student characteristics, intervention characteristics, the type of reading skill being measured, and how the studies were conducted. Two factors mattered: the amount of instruction students received and the reading skill being measured. Students who received more instruction tended to show greater improvements. The interventions also had larger effects on word reading and spelling outcomes than on reading comprehension outcomes. In addition, interventions that included spelling instruction alongside word reading instruction were more effective than those that did not include a spelling component. The researchers also found insufficient evidence that programs labeled as multisensory are more effective than other evidence-based reading approaches that are not described as multisensory.
How Did the Researchers Find This?
The researchers conducted a meta-analysis that included 53 experimental or quasi-experimental intervention studies conducted between 1980 and 2020 that aimed to improve reading outcomes for students with or at risk for dyslexia in Grades K-5.
What Are the Implications of These Findings?
These findings suggest that students with or at risk for dyslexia benefit from reading interventions that include foundational skills instruction. Providing a greater amount of intervention may also be one way to increase reading gains. Importantly, however, the findings do not indicate that simply increasing instructional time will automatically produce better outcomes; dosage was examined across studies alongside other characteristics of the interventions. The findings also suggest that schools may be able to provide effective intervention in small groups rather than relying exclusively on one-on-one instruction. Moreover, because interventions that included spelling instruction in addition to word reading instruction were more effective than those without a spelling component, schools may want to consider multicomponent interventions that address both of these skills. However, findings from this study do not support the prioritization of interventions that describe themselves as multisensory over other evidence-based interventions that do not use this label.
What Are the Limitations of This Paper?
Most of the studies involved younger elementary students. Forty-five of the 53 studies were conducted with students in Grades K–2, which means the evidence base is much stronger for younger elementary students than Grades 3–5. The authors note that the mean effect might have been different if grade levels had been represented more evenly.
The studies varied considerably in their effects. There was significant heterogeneity among the study effects. That’s why the researchers conducted a meta-regression to examine factors that might explain those differences.
The findings apply to a specific population and type of intervention. The researchers specifically included students meeting their criteria for word reading difficulties/risk and interventions containing foundational skills instruction. They did not study every type of reading intervention or every student with reading difficulties. For example, interventions that only addressed reading comprehension, vocabulary, oral language, or text reading fluency were excluded.
Terms to Know
Dosage: Dosage is the amount of intervention students receive, including the frequency and the duration of instructional time and the overall length of the intervention.
Experimental research: Experimental research aims to determine whether a certain treatment influences a measurable outcome—for example, whether a certain instructional method influences students’ reading comprehension scores. To do this, participants are divided into two groups: an experimental group, which receives the treatment, and a control group, which does not receive the treatment. In an experimental study, these groups are randomly assigned, meaning each participant has equal probability of being in either the treatment or the control group. Both groups are tested before and after the treatment, and their results are compared.
Heterogeneity: Heterogeneity is the extent to which the results differed across the studies included in the meta-analysis. For example, some studies may have found larger improvements in students’ reading skills than others.
Meta-analysis: A meta-analysis is a study that synthesizes the results of separate studies addressing the same research question by systematically identifying and evaluating studies on a certain phenomenon, pooling their data and conducting statistical analyses, and interpreting the collective results.
Meta-regression: A meta-regression is a statistical method researchers use to investigate whether differences among studies (such as students’ grade levels, intervention dosage, or instructional approaches) help explain why the results varied.
Quasi-experimental: A quasi-experimental study is similar to an experimental study except that participants are not randomly assigned to groups. In educational research, groups often are assigned by classroom rather than through random assignment, making this kind of research quasi-experimental.
References
Hall, C., Dahl-Leonard, K., Cho, E., Solari, E. J., Capin, P., Conner, C. L., Henry, A. R., Cook, L., Hayes, L., Vargas, I., Richmond, C. L. and Kehoe, K. F. (2023). Forty years of reading intervention research for elementary students with or at risk for dyslexia: A systematic review and meta-analysis. Reading Research Quarterly, 58(2). https://doi.org/10.1002/rrq.477