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	Dubbelblind placebokontrollerad experimentell design med för- och eftermätning	Solomon Four-Group Design
Ämnesområde	Försöksplanering	Försöksplanering
Familj	Process / pipeline	Process / pipeline
Ursprungsår	Mid-20th century (combined form widely adopted 1960s onward)	1949
Upphovsperson	Campbell & Stanley (formalized pretest-posttest design, 1963); double-blind blinding convention developed in clinical pharmacology (19th-20th century)	Richard L. Solomon
Typ	True experimental design	True experimental design
Ursprungskälla	Campbell, D. T., & Stanley, J. C. (1963). Experimental and quasi-experimental designs for research. In N. L. Gage (Ed.), Handbook of Research on Teaching (pp. 171-246). Rand McNally.	Solomon, R. L. (1949). An extension of control group design. Psychological Bulletin, 46(2), 137–150.
Alias	DB-pretest-posttest design, double-blind pre-post design, masked pretest-posttest RCT, double-masked pre-post experiment	Solomon design, four-group design, Solomon four-group control design, S4GD
Närliggande	5	5
Sammanfattning	The double-blind pretest-posttest experimental design is a true experiment in which participants are randomly assigned to treatment and control conditions, outcome data are collected both before and after the intervention, and neither participants nor outcome assessors know which condition each participant received. Combining baseline measurement with strong blinding, the design controls for both pre-existing group differences and expectancy-driven bias, making it a gold-standard approach in clinical and behavioral research.	The Solomon Four-Group Design extends the classic pretest-posttest control-group design by adding two groups that receive no pretest, enabling researchers to detect whether the pretest itself alters participants' responses to the treatment. Introduced by Richard L. Solomon in 1949, it remains the gold standard for isolating the independent effect of a pretest and for obtaining unbiased estimates of treatment efficacy.