Jämför metoder

	Faktoriell experimentell design med förtest och eftertest	Solomon Four-Group Design
Ämnesområde	Försöksplanering	Försöksplanering
Familj	Process / pipeline	Process / pipeline
Ursprungsår	1963 (canonical formalization)	1949
Upphovsperson	Codified by Donald T. Campbell and Julian C. Stanley	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. Rand McNally.	Solomon, R. L. (1949). An extension of control group design. Psychological Bulletin, 46(2), 137–150.
Alias	factorial pre-post design, factorial repeated-measures pretest-posttest design, multi-factor pretest-posttest design, FPPD	Solomon design, four-group design, Solomon four-group control design, S4GD
Närliggande	6	5
Sammanfattning	A factorial pretest-posttest experimental design combines the simultaneous manipulation of two or more independent variables (factors) with measurement of the dependent variable both before and after treatment. This structure allows researchers to assess the main effect of each factor, all possible interaction effects between factors, and the magnitude of change from pretest to posttest — all within a single, fully randomised experiment.	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.