Percentage of Nonoverlapping Data
The Percentage of Nonoverlapping Data (PND) is a simple effect-size index for single-case research that summarizes how strongly a treatment phase departs from baseline by counting the share of treatment data points that lie beyond the most extreme baseline point. Introduced by Thomas Scruggs, Margo Mastropieri, and Glendon Casto in 1987 to allow quantitative synthesis of single-subject studies, it produces a single 0–100% number that complements visual analysis and can be aggregated across cases in a meta-analysis of single-case designs.
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Sources
- Scruggs, T. E., Mastropieri, M. A., & Casto, G. (1987). The quantitative synthesis of single-subject research: Methodology and validation. Remedial and Special Education, 8(2), 24–33. DOI: 10.1177/074193258700800206 ↗
- Parker, R. I., Vannest, K. J., & Davis, J. L. (2011). Effect size in single-case research: A review of nine nonoverlap techniques. Behavior Modification, 35(4), 303–322. DOI: 10.1177/0145445511399147 ↗
How to cite this page
ScholarGate. (2026, June 22). Percentage of Nonoverlapping Data for Single-Case Effect Estimation. ScholarGate. https://scholargate.app/en/social-work/percentage-nonoverlapping-data
Which method?
Set this method beside its closest kin and read them side by side — the library lays the books on the table; the choice is yours.
- Nonoverlap of All PairsSocial Work↔ compare
- Single-System DesignSocial Work↔ compare
- Tau-USocial Work↔ compare
- Visual Analysis of Single-Case DataSocial Work↔ compare