Confronta i metodi

	Disegno Solomon a quattro gruppi randomizzato a grappoli	Disegno di Solomon a Quattro Gruppi
Campo	Disegno sperimentale	Disegno sperimentale
Famiglia	Process / pipeline	Process / pipeline
Anno di origine	1949 (Solomon design); cluster extension formalized in 1990s	1949
Ideatore	Richard L. Solomon (four-group logic, 1949); cluster randomization methods developed by Murray and colleagues in the 1990s	Richard L. Solomon
Tipo	Experimental design	True experimental design
Fonte seminale	Solomon, R. L. (1949). An extension of control group design. Psychological Bulletin, 46(2), 137–150.	Solomon, R. L. (1949). An extension of control group design. Psychological Bulletin, 46(2), 137–150.
Alias	CR-S4GD, cluster-randomized four-group design, group-randomized Solomon design, Solomon four-group cluster trial	Solomon design, four-group design, Solomon four-group control design, S4GD
Correlati	6	5
Sintesi	The cluster randomized Solomon four-group design combines cluster randomization — assigning intact groups such as schools, clinics, or communities to conditions — with the Solomon four-group structure that isolates the effect of pretesting. Four clusters (or sets of clusters) are created: two receive the treatment and two serve as controls, with only one treatment cluster and one control cluster receiving a pretest, while the others go straight to the posttest. This structure simultaneously controls for pretest sensitization and the logistical constraint that individual randomization is infeasible.	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.