01-26-2017 06:01 AM - edited 01-26-2017 11:20 AM
I want to compute the effect size of a variable.
mean group1 = 10,978
mean group 2 = 9,228
standard deviation 1 = 0,8402
standard deviation 2 = 0,5767
correlation = 0,59105
I calculated the effecct size with g*power, but the result is 2,56. This is a very high value ?
Can I compute this in SAS with this given information, or am I doing something wrong?
01-26-2017 08:22 AM - edited 01-26-2017 11:21 AM
thank you for the reaction. I have a dataset with 1 group measured 2 times, so I used a paired t-test. But as you see when I calculate this in g*power I get a huge effect size. The effect size that I get when using method 1 is different than when I use method 2.
I compute first the effect size in g*power in the additional window (effect size = 2,56).
Then I use this value to calculate the power (power = 1).
I first calculate the power in SAS (power = 0,9999).
Then I use this power value to calculate the effect size in G*power (effect size = 0,68)
Can somebody explain this?