# multiple comparisons with multiple regressions?

#### meema

##### New Member
Hi there, I'm hoping that someone can answer my query or point me in the direction of a reliable source to find out more.

My question is - Is the issue of multiple comparisons relevant to a multiple regression? I've read one article suggesting a bonferoni correction, but a journal article I read stated the authors didn't use a correction as a regression analyses data simultaneously.

Any help would be gratefully received, thanks

#### meema

##### New Member
Incase this helps anyone with a similar question to mine - I've found a reference to a book which explains how to conduct an extension of fisher's protected t-test for a multiple regression (unfortunately I can't get hold of this book!). Cohen definately advises taking the issue of multiple comparisons seriously in MRC:

Cohen and Cohen (1983) Applied MRC analysis for the behavioral sciences

#### meema

##### New Member

But I'm now having a hard time finding out on the internet how to calculate Fisher's test for a multiple regression. Any ideas?

#### bbkaran

##### New Member
Multiple Regression

As I understand multiple regression involves one dep variable and several (multi) indep variables. So we have:

y=a1x1+a2x2+a3x3+...+amxm

where:
a1,a2,...,am are the coefficients; and
z1,x2,...,xm are the 'm' indep variables of length, say, n.
Here we are assessing the contributions x1,x2,...,xm to y.

I am not sure what you mean by "multiple comparisons". Perhaps this is the reason
no responded to your post. You seem to assume everyone knows what the problem is.