Compara mètodes

	Test dels signes	Test de Friedman
Camp	Estadística	Estadística
Família	Hypothesis test	Hypothesis test
Any d'origen	1946	1937
Autor original	W. J. Dixon & A. M. Mood	Milton Friedman
Tipus	Nonparametric median test	Nonparametric repeated-measures comparison (by ranks)
Font seminal	Dixon, W. J. & Mood, A. M. (1946). The statistical sign test. Journal of the American Statistical Association, 41(236), 557–566.	Friedman, M. (1937). The use of ranks to avoid the assumption of normality implicit in the analysis of variance. Journal of the American Statistical Association, 32(200), 675–701.
Àlies	İşaret Testi (Sign Test), one-sample sign test, paired sign test	Friedman two-way analysis of variance by ranks, Friedman rank test, Friedman Testi
Relacionats	4	2
Resum	The sign test is the simplest nonparametric hypothesis test for deciding whether the median of paired differences — or of a single sample — differs significantly from a hypothesised value. Formalised by W. J. Dixon and A. M. Mood in 1946, it imposes virtually no distributional assumptions and can be applied to any data where individual differences can be classified as positive or negative.	The Friedman test is a nonparametric hypothesis test that compares three or more related conditions measured on the same blocks or subjects, serving as the rank-based alternative to repeated-measures ANOVA. It was introduced by Milton Friedman in 1937 and works on ordinal or continuous data without assuming normality.