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Publication bias in studies of an applied behavior‐analytic intervention: An initial analysis
Author(s) -
Sham Elyssa,
Smith Tristram
Publication year - 2014
Publication title -
journal of applied behavior analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 76
eISSN - 1938-3703
pISSN - 0021-8855
DOI - 10.1002/jaba.146
Subject(s) - publication bias , psychology , autism , meta analysis , confidence interval , psychological intervention , intervention (counseling) , clinical psychology , statistics , developmental psychology , psychiatry , medicine , mathematics
Publication bias arises when studies with favorable results are more likely to be reported than are studies with null findings. If this bias occurs in studies with single‐subject experimental designs (SSEDs) on applied behavior‐analytic (ABA) interventions, it could lead to exaggerated estimates of intervention effects. Therefore, we conducted an initial test of bias by comparing effect sizes, measured by percentage of nonoverlapping data (PND), in published SSED studies ( n = 21) and unpublished dissertations ( n = 10) on 1 well‐established intervention for children with autism, pivotal response treatment (PRT). Although published and unpublished studies had similar methodologies, the mean PND in published studies was 22% higher than in unpublished studies, 95% confidence interval (4%, 38%). Even when unpublished studies are included, PRT appeared to be effective (PND M = 62%). Nevertheless, the disparity between published and unpublished studies suggests a need for further assessment of publication bias in the ABA literature.