Dear Colleagues,
Most of my work is descriptive and qualitative, and the
statistical procedures I typically use are simple things like
averages and standard deviations. However, a situation has
arisen requiring more statistical knowledge than I possess,
in which case I hope that someone out there in cyberspace
may advise me how to proceed.
I have quantified experimentally the activity ("X") of a
half-dozen different products (A-F). These 6 commercial
products all contain the same "active ingredient" over a
range of different concentrations (and a couple of products
share the same "active ingredient" concentration). The
problem arises from the fact that these 6 commercial
preparations each contain different additives that may
possibly impact on the observed activity, and no two
products contain identical sets of additives. Under these
circumstances, is there a statistical procedure that would
enable me to distinguish the effect of the "active
ingredient" per se from the mitigating effects (either
positive or negative) of the additives? At first I thought
of doing a simple oneway ANOVA of the 6 products
side-by-side, but then thought that this might not be
able to distinguish between the effects of the "active
ingredient" per se from that of the "active ingredient
+ additives". Any further suggestions would be most
welcome. I have access to two statistics software
packages: MINITAB 11.21 (preferred) and Excel 97,
but may be able to find other packages if I hunt around
long enough.
Kindly respond to me _directly_ at
[EMAIL PROTECTED]
Thanks in advance to all responders,
S. Shapiro
[EMAIL PROTECTED]
=================================================================
Instructions for joining and leaving this list and remarks about
the problem of INAPPROPRIATE MESSAGES are available at
http://jse.stat.ncsu.edu/
=================================================================
