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.
Source record
Citations copied verbatim from the method’s source record. No claim-level verification is inferred from them.
- 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
Curated claims
Claims persisted in the evidence ledger, each with its own assessment.
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Related methods
Generated from the method graph and shown as machine-suggested relations — no evidence claim is inferred.