Dear Statalisters
I'm putting together a prospective protocol for a long term stability study
(26 months) that will ultimately yield a series of 17 data points over time.
Each data point will be an average of 5 replicates from a test. I
anticipate plotting a regression of average intensity (the test result)over
time, to yield a linear equation. Is there a common test for inferring an
effect due to time, such as rejecting a null hypothesis of slope=0? Can I
calculate power? Are five replicates at each point sufficient?
Thanks for any guidance - even if its RTFM (though a pointer to a specific
section would be appreciated - the help file for -regress- is dizzyingly
large)
John Wallace | Research Associate | Test Method Development
AFFYMETRIX, INC. | 3380 Central Expressway | Santa Clara, CA 95051 | Tel:
408-731-5574 | Fax: 408-481-0435
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