The Relative Effects of Group Size on Reading Progress of Older Students With Reading Difficulties


This study reports findings on the relative effects from a yearlong secondary intervention that contrasted large-group, small-group, and school-provided word study, vocabulary development, fluency, and comprehension interventions with seventh- and eighth-graders with reading difficulties. Findings indicate that few statistically significant results or clinically significant gains were associated with group size or intervention. Findings also indicate that a significant acceleration of reading outcomes for seventh- and eighth-graders from high-poverty schools is unlikely to result from a 50-minute daily class. Instead, the findings indicate, achieving this outcome will require more comprehensive models, including more extensive intervention (e.g., more time, even smaller groups), interventions that are longer in duration (multiple years), and interventions that vary in emphasis, based on specific students’; needs (e.g., increased focus on comprehension or word study).


Vaughn, S., Wanzek, J., Wexler, J., Barth, A., Cirino, P. T., Fletcher, J. M., . . . Francis, D. (2010). The relative effects of group size on reading progress of older students with reading difficulties. Reading and Writing, 23, 931–956. doi:10.1007/s11145-009-9183-9