Studentized Range Distribution (2 of 3)
The formula for the studentized t is:
Notice that the only difference between the formulas is that "2" in the denominator of the t-test is not present in the formula for the studentized t. The value of ts is therefore the square root of 2 = 1.414 times the value of t. The significance test using the studentized t compensates for the difference in the formulas by using a critical value of t that is 1.414 times the value that would have been used if the formulas were the same. If an experiment were conducted with two groups and 13 subjects per group, then a t either less than −2.06 or greater than +2.06 would be needed to be significant at the 0.05 level. Since 1.414 x 2.06 = 2.91, a t s either less than -2.91 or greater than 2.91 would be needed to be significant.