Hi R! I attempt to clear my question through this example. We know that the default functions for "t.test" is t.test(x, y = NULL, alternative = c("two.sided", "less", "greater"), mu = 0, paired = FALSE, var.equal = FALSE, conf.level = 0.95, ...) Suppose, I want to create a new function where "paired=TRUE". What is the simpler way of creating such functions? I did try, but without much success. Thanks in advance -- Prabhanjan N. Tattar Lead Statistician CustomerXPS Bangalore [[alternative HTML version deleted]]