مقایسهٔ روش‌ها

	طرح چهار گروهی سلیمان مسدود شده	آزمایش عاملی
حوزه	طراحی آزمایش	طراحی آزمایش
خانواده	Process / pipeline	Process / pipeline
سال پیدایش	1949 (base); blocking extension applied in behavioral and social sciences from mid-20th century onward	1926–1935
پدیدآور	Richard L. Solomon (base design, 1949); blocking integrated from classical experimental design tradition (Fisher, 1935)	Ronald A. Fisher
نوع	Experimental design	Quantitative experimental design
منبع بنیادین	Solomon, R. L. (1949). An extension of control group design. Psychological Bulletin, 46(2), 137–150.	Fisher, R. A. (1935). The Design of Experiments. Oliver and Boyd.
نام‌های دیگر	Blocked S4G, randomized blocked Solomon design, Solomon four-group with blocking	factorial design, factorial ANOVA design, multi-factor experiment, crossed-factor design
مرتبط	6	6
خلاصه	The blocked Solomon four-group design combines Solomon's classic four-group structure — which disentangles pretest sensitization effects from treatment effects — with blocking on a known nuisance variable. Participants are first grouped into homogeneous blocks (e.g., by baseline ability, gender, or site), then randomly assigned within each block to one of four conditions: pretested treatment, pretested control, unpretested treatment, and unpretested control. This structure simultaneously controls for maturation, pretest reactivity, and block-level variance, making it one of the strongest quasi-controlled experimental frameworks available.	A factorial experiment is an experimental design in which two or more independent variables (factors) are manipulated simultaneously, and every combination of their levels is tested. Introduced by Ronald Fisher in the 1920s–1930s, it is the standard approach whenever a researcher needs to detect not only the main effect of each factor but also whether the effect of one factor depends on the level of another — the interaction effect.