Research Design Types
Research design is the overall structure and strategy of a study, encompassing decisions about how to collect, organize, and analyze data to answer research questions. Major design types include experimental (randomized controlled trials), quasi-experimental (non-random assignment), observational (no manipulation), and qualitative (exploratory, interpretive). Donald T. Campbell and Julian Stanley's 1963 seminal work established systematic terminology for internal validity threats in each design type. Modern classifications (Campbell et al., 2002; Creswell & Plano Clark, 2011) also include mixed-methods designs combining quantitative and qualitative elements.
Source record
Citations copied verbatim from the method’s source record. No claim-level verification is inferred from them.
- Campbell, D. T., & Stanley, J. C. (1963). Experimental and Quasi-Experimental Designs for Research. Rand McNally. · URL
- Creswell, J. W., & Plano Clark, V. L. (2011). Designing and Conducting Mixed Methods Research (2nd ed.). SAGE Publications. · URL
- Shadish, W. R., Cook, T. D., & Campbell, D. T. (2002). Experimental and Quasi-Experimental Designs for Generalized Causal Inference. Houghton Mifflin. · URL
Curated claims
Claims persisted in the evidence ledger, each with its own assessment.
This view does not invent a claim assessment when the ledger has none.
Related methods
Generated from the method graph and shown as machine-suggested relations — no evidence claim is inferred.