Peer Effects in Language Therapy for Preschoolers With Developmental Language Disorder: A Pilot Study [High/low performing student pairing]
Schmitt, Mary B., Tambyraja, Sherine, & Siddiqui, Seham (2022). American journal of speech-language pathology, 31(4), 1854–1867.
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examining19Students, gradePK
Practice Guide
Review Details
Reviewed: February 2026
- Practice Guide (findings for Peer presence in language therapy - Schmitt (2022) )
- Randomized Controlled Trial
- Meets WWC standards with reservations because it is a randomized controlled trial with high attrition, but the analytic intervention and comparison groups satisfy the baseline equivalence requirement.
This review may not reflect the full body of research evidence for this intervention.
Evidence Tier rating based solely on this study. This intervention may achieve a higher tier when combined with the full body of evidence.
Findings
|
Outcome measure |
Comparison | Period | Sample |
Intervention mean |
Comparison mean |
Significant? |
Improvement index |
|---|---|---|---|---|---|---|---|
|
Clinical Evaluation of Language Fundamentals (CELF) Preschool - Word Structure subtest |
Peer presence in language therapy - Schmitt (2022) vs. Business as usual |
0 Days |
Full sample;
|
2.00 |
0.33 |
No |
-- |
Evidence Tier rating based solely on this study. This intervention may achieve a higher tier when combined with the full body of evidence.
Sample Characteristics
Characteristics of study sample as reported by study author.
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Female: 26%
Male: 74% -
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Race Black 16% Other or unknown 58% Two or more races 5% White 21% -
Ethnicity Hispanic 53% Other or unknown 47% -
Eligible for Free and Reduced Price Lunch Other or unknown 100%
Study Details
Setting
The study took place in one Head Start center located in a southern U.S. state.
Study sample
The researchers randomly assigned 10 preschool children to the intervention group and 11 preschool children to the comparison group. The analyses included 10 children in the intervention group and 9 children from the comparison group. Children with delayed language development (DLD), based on scores on three subtests of the Clinical Evaluation of Language Fundamentals Preschool – 2nd Edition, were eligible for the study. Approximately 74 percent of the students were male, and 26 percent were female. In order from largest to smallest (reporting only those categories in the study): Twenty-one percent were White, 16 percent were Black, 5 percent were multiracial, and 58 percent were of unknown race. Fifty-three percent were Hispanic or Latino and 47 percent did not report ethnicity.
Intervention Group
The intervention aims to enhance language education for preschoolers with DLD by providing them with language instruction alongside peers with typically developing language (TDL). Each child in the intervention group was paired with a peer with TLD. Each pair participated in speech language therapy administered by a graduate student that was not aware of the study group assignment for each participant and whether participants had a diagnosis of DLD. The intervention took place in the Head Start classroom over 8 weeks. Each session was 45 minutes in duration and sessions were conducted once each week. The intervention sessions included three 15-minute components, including an interactive book reading, a gross motor activity, and a craft.
Comparison Group
Children in the comparison condition received the same speech language therapy as children in the intervention condition, but paired with another DLD peer, rather than a TDL peer. The speech language therapy was administered over the same duration (45-minute sessions, weekly for 8 weeks).
Support for implementation
The intervention was conducted by graduate research assistants pursuing degrees in speech language pathology. The Principal Investigator oversaw the treatment sessions for both the intervention and comparison groups. The graduate research assistants who provided intervention to the participating students were blind to the student’s DLD status and study condition.
An indicator of the effect of the intervention, the improvement index can be interpreted as the expected change in percentile rank for an average comparison group student if that student had received the intervention.
For more, please see the WWC Glossary entry for improvement index.
An outcome is the knowledge, skills, and attitudes that are attained as a result of an activity. An outcome measures is an instrument, device, or method that provides data on the outcome.
A finding that is included in the effectiveness rating. Excluded findings may include subgroups and subscales.
The sample on which the analysis was conducted.
The group to which the intervention group is compared, which may include a different intervention, business as usual, or no services.
The timing of the post-intervention outcome measure.
The number of students included in the analysis.
The mean score of students in the intervention group.
The mean score of students in the comparison group.
The WWC considers a finding to be statistically significant if the likelihood that the finding is due to chance alone, rather than a real difference, is less than five percent.
The WWC reviews studies for WWC products, Department of Education grant competitions, and IES performance measures.
The name and version of the document used to guide the review of the study.
The version of the WWC design standards used to guide the review of the study.
The result of the WWC assessment of the study. The rating is based on the strength of evidence of the effectiveness of the intervention. Studies are given a rating of Meets WWC Design Standards without Reservations, Meets WWC Design Standards with Reservations, or >Does Not Meet WWC Design Standards.
A related publication that was reviewed alongside the main study of interest.
Study findings for this report.
Based on the direction, magnitude, statistical significance, and sample size of the findings within a domain, the WWC assigns effectiveness ratings as one of the following: Tier 1 (strong evidence), Tier 2 (moderate evidence), Tier 3 (promising evidence), uncertain effects, and negative effects. For more detail, please see the WWC Handbook.
The WWC may review studies for multiple purposes, including different reports and re-reviews using updated standards. Each WWC review of this study is listed in the dropdown. Details on any review may be accessed by making a selection from the drop down list.
Tier 1 Strong indicates strong evidence of effectiveness,
Tier 2 Moderate indicates moderate evidence of effectiveness, and
Tier 3 Promising indicates promising evidence of effectiveness,
as defined in the
non-regulatory guidance for ESSA
and the regulations for ED discretionary grants (EDGAR Part 77).