Stata The Stata listserver
[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

st: Power calculation for regression

From   "Wallace, John" <>
To   "''" <>
Subject   st: Power calculation for regression
Date   Mon, 23 Feb 2004 10:36:11 -0800

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

John Wallace | Research Associate | Test Method Development
AFFYMETRIX, INC. | 3380 Central Expressway | Santa Clara, CA 95051 | Tel:
408-731-5574 | Fax:  408-481-0435
*   For searches and help try:

© Copyright 1996–2024 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index