CVtotal ≠ CVinter № 42 [Power / Sample Size]

posted by AngusMcLean – USA, 2013-01-11 18:34 (4912 d 03:10 ago) – Posting: # 9828
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Thank you Helmut: this is a confusinbg field. It seems that the English language description of the output you get is poor. Both WinNonlin and NCSS are from here. The lack of clarity is the major problem and of course statistics is a confusing subject especially when the terms used are not well described or ccan be equivalent.

I compared the output from WinNonlin and NCSS: the variance term is exactly the same. WinNonlin calls the variance term "variance residual" NCSS provides a row in a Table and calls it the Error term of the 2 treatments A and B and it refers to it as the Mean Square Error (MSE) in another part of the output. They are in my example exactly the same number.

So it seems that indeed it is the total error or total variance not the inter subject variance we have.

So that means that the value we have is a convolution of the intersubect error and intrasubject error? Or is there another factor I am overlooking?

And as previously referred to is higher than intersubject variance so using it provides a higher estimate of sample size.


Angus

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