re: Re: st: Configuring Data to percentage ratios

[David Airey <david.airey@vanderbilt.edu>]

> Pharmacology journals, at least in the past, allowed you to divide 
> individual
> fluorescence values in each of the drug groups by the mean of the 
> control group
> values as the divisor, and then calculate SEs or SDs from the 
> quotients.  This
> treats the control group's mean as if it were fixed, known.  It gives 
> an SE
> that is symmetric about the ratio of the means.

This is still allowed. I would love to read a reference in which it is 
shown to hurt rather than help. Being in a pharmacology department but 
coming from other fields, the practice bothers me.

Especially in pharmacology people are concerned about relative 
effects--"fold above control" is a common phrase.

"Fieller's theorem" comes up here too:

http://www.stata.com/help.cgi?pkequiv

I'm still Googling...

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