International Portal of Teacher Education

Source: Review of Educational Research. Vol. 79, Iss. 3; p. 1202-1242. (September 2009).
(Reviewed by the Portal team)

The purpose of this study was to synthesize randomized control trials and quasi-experimental research on instructional approaches that enhance the mathematics performance of school-age students with learning disabilities.

Selection of Studies: Literature Review
In this study, the authors defined mathematical interventions as instructional practices and activities designed to enhance the mathematics achievement of students with learning disabilities. The authors reviewed all studies published from January 1971 to August 2007 that focused on mathematics interventions to improve the mathematics proficiency of school-age students with learning disabilities.

Criteria for Inclusion
Three criteria were used to determine study inclusion.
1. Focus of the study had to be an evaluation of the effectiveness of a well-defined method (or methods) for improving mathematics proficiency.
2. Design of the Study - studies were included if strong claims of causal inference could be made, namely, randomized controlled trials or quasi-experimental designs.
3. Participants in the Study - the participants had to be students with an identified learning disability. Studies that also included students without learning disabilities were included if one of the following criteria were met:

(a) Separate outcome data were presented so that effect sizes could be computed separately for students with learning disabilities, or
(b) if separate outcome data were not presented for students with learning disabilities, then more than 50% of the study participants were students with learning disabilities.

A total of 42 intervention studies were examined in this meta-analysis.
The authors examined the impact of four categories of instructional components:
(a) approaches to instruction and/or curriculum design,
(b) formative assessment data and feedback to teachers on students' mathematics performance,
(c) formative data and feedback to students with learning disabilities on their performance, and
(d) peer-assisted mathematics instruction.
All instructional components except for student feedback with goal-setting and peer-assisted learning within a class resulted in significant mean effects ranging from 0.21 to 1.56.

The authors also examined the effectiveness of these components conditionally, using hierarchical multiple regressions. Two instructional components provided practically and statistically important increases in effect size-teaching students to use heuristics and explicit instruction.
Limitations of the study, suggestions for future research, and applications for improvement of current practice are discussed.