Voici ma trame de données:
Group <- c("G1","G1","G1","G1","G1","G1","G1","G1","G1","G1","G1","G1","G1","G1","G1","G2","G2","G2","G2","G2","G2","G2","G2","G2","G2","G2","G2","G2","G2","G2","G3","G3","G3","G3","G3","G3","G3","G3","G3","G3","G3","G3","G3","G3","G3")
Subject <- c("S1","S2","S3","S4","S5","S6","S7","S8","S9","S10","S11","S12","S13","S14","S15","S1","S2","S3","S4","S5","S6","S7","S8","S9","S10","S11","S12","S13","S14","S15","S1","S2","S3","S4","S5","S6","S7","S8","S9","S10","S11","S12","S13","S14","S15")
Value <- c(9.832217741,13.62390117,13.19671612,14.68552076,9.26683366,11.67886655,14.65083473,12.20969772,11.58494621,13.58474896,12.49053635,10.28208078,12.21945867,12.58276212,15.42648969,9.466436017,11.46582655,10.78725485,10.66159358,10.86701127,12.97863424,12.85276916,8.672953949,10.44587257,13.62135205,13.64038394,12.45778874,8.655142642,10.65925259,13.18336949,11.96595556,13.5552118,11.8337142,14.01763101,11.37502161,14.14801305,13.21640866,9.141392359,11.65848845,14.20350364,14.1829714,11.26202565,11.98431285,13.77216009,11.57303893)
data <- data.frame(Group, Subject, Value)
Ensuite, je lance un modèle d'effets mixtes linéaires pour comparer la différence des 3 groupes sur "Valeur", où "Sujet" est le facteur aléatoire:
library(lme4)
library(lmerTest)
model <- lmer (Value~Group + (1|Subject), data = data)
summary(model)
Les résultats sont:
Fixed effects:
Estimate Std. Error df t value Pr(>|t|)
(Intercept) 12.48771 0.42892 31.54000 29.114 <2e-16 ***
GroupG2 -1.12666 0.46702 28.00000 -2.412 0.0226 *
GroupG3 0.03828 0.46702 28.00000 0.082 0.9353
Cependant, comment comparer Group2 avec Group3? Quelle est la convention dans l'article académique?
Une fois que vous avez ajusté votre
lmer
modèle, vous pouvez effectuer des procédures ANOVA, MANOVA et plusieurs comparaisons sur l'objet modèle, comme ceci:Quant à la convention dans les articles académiques, cela va beaucoup varier selon le domaine, la revue et le sujet spécifique. Donc, dans ce cas, passez en revue les articles connexes et voyez ce qu'ils font.
la source
summary(glht(model, linfct = mcp(Group = "Tukey")))
. Si vous souhaitez voir la description académique / statistique complète des différents tests qui peuvent être effectués, consultez les références dans?glht
etmulticomp
plus généralement. Je pense que Hsu 1996 serait le principal.mcp
fonction, leGroup = Tukey
juste moyen de comparer tous les groupes par paire dans la variable "Group". Cela ne signifie pas un ajustement Tukey.