[R] using a noisy variable in regression (not an R question)

[Stephan Kolassa]

Hi Juliet,

Juliet Hannah schrieb:
> 
> One simple thing to try would be to form categories
> 

Simple but problematic. Frank Harrell put together a wonderful page 
detailing all the issues with categorizing continuous data:
http://biostat.mc.vanderbilt.edu/twiki/bin/view/Main/CatContinuous

So: keep your data continuous.

Apart from that, I would second John's recommendation to try to get 
samples at the same point in time (and, if it is cortisol, stay away 
from smokers etc.).

Best wishes
Stephan