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ERIC Number: EJ1100725
Record Type: Journal
Publication Date: 2016-May
Pages: 25
Abstractor: As Provided
ISSN: ISSN-1944-7515
Comparing Single Case Design Overlap-Based Effect Size Metrics from Studies Examining Speech Generating Device Interventions
Chen, Mo; Hyppa-Martin, Jolene K.; Reichle, Joe E.; Symons, Frank J.
American Journal on Intellectual and Developmental Disabilities, v121 n3 p169-193 May 2016
Meaningfully synthesizing single case experimental data from intervention studies comprised of individuals with low incidence conditions and generating effect size estimates remains challenging. Seven effect size metrics were compared for single case design (SCD) data focused on teaching speech generating device use to individuals with intellectual and developmental disabilities (IDD) with moderate to profound levels of impairment. The effect size metrics included percent of data points exceeding the median (PEM), percent of nonoverlapping data (PND), improvement rate difference (IRD), percent of all nonoverlapping data (PAND), Phi, nonoverlap of all pairs (NAP), and Tau[subscript novlap]. Results showed that among the seven effect size metrics, PAND, Phi, IRD, and PND were more effective in quantifying intervention effects for the data sample (N = 285 phase or condition contrasts). Results are discussed with respect to issues concerning extracting and calculating effect sizes, visual analysis, and SCD intervention research in IDD.
American Association on Intellectual and Developmental Disabilities. P.O. Box 1897, Lawrence, KS 66044-1897. Tel: 785-843-1235; Fax: 785-843-1274; e-mail:; Web site:
Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Audience: N/A
Language: English
Sponsor: Health Resources and Services Administration (DHHS), Maternal and Child Health Bureau
Authoring Institution: N/A
Grant or Contract Numbers: 2T73MC128350300