Sample Size for Unpaired t Test


Menu location: Analysis_Sample Size_Unpaired t.


This function gives you the minimum number of experimental subjects needed to detect a true difference DELTA in population means with power POWER and two sided type I error probability ALPHA (Dupont, 1990; Pearson and Hartley, 1970).


Information required


Practical issues


Technical validation

The estimated sample size n is calculated as the solution of:

- where d = delta/sd, α = alpha, β = 1 - power, m is the number of control subjects per experimental subject, and tv,p is a Student t quantile with v degrees of freedom and probability p. n is rounded up to the closest integer.