Hi, Try this: set.seed(24) ?b1<- sample(1:40,20,replace=TRUE) ?set.seed(28) ?a1<- sample(30:50,20,replace=TRUE) t_test_apparie <- function(x,y) { t.test(x,y,paired=TRUE,alternative = "greater")$p.value } t_test_apparie(a1,b1) #[1] 6.571404e-08 A.K.>Hi, > >I have written this function : > >t_test_apparie <- function(x,y) >{ >t.test(x,y,paired=TRUE,alternative = "greater") >} > >I would like that ONLY the p-value gets returned. How would I do that? > >Thanks.