Comparing groups - using ANOVA but unsure on various points, help greatly appreciated!

#1
Hi all,
I'm trying to do some stats on a small dataset but I'm a bit of a novice and could use some expert advice. I basically have 5 samples each from 6 different participants, which have been stored under different conditions before testing. I am comparing to look at the impact storage condition has on the eventual test result. So for each sample I have a 'control', tested on the day it was taken, one stored for 7 days at room temp, one stored for 7 days at 37C, one stored for 14 days at room temp, and one stored for 14 days at 37C. I need to compare the 4 storage treatment samples to the control.
Each participant has a different baseline test result as their control, so I can't combine the 6 participants to get a mean for each condition.
I'm unclear what the best test would be. Should I run an ANOVA separately on each participant? Are my values matched (so repeated measures)? Do I need a one-way ANOVA, or two-way because of the temp and time being changed? I am using graphpad to run the analysis if that is useful info.
Thanks very much for any help you can give.
 

Miner

TS Contributor
#2
You will probably have to use a General Linear Model instead of the standard ANOVA to include the control in the analysis. A different approach that would allow you to use a 2-way ANOVA would be to take the mean of the control sample for subject 1 and subtract that from all of the subject 1 results. Then take the mean of the control sample for subject 2 and subtract that from all of the subject 2 results. Repeat for subjects 3 - 6, then perform a 2-way ANOVA on temperature and duration using subjects as replicates.