Dear Yuelin, Another paper critical of post-hoc power calculations is Hoenig and Heisey, 2001. "The Abuse of Power: The Pervasive Fallacy of Power Calculations for Data Analysis." The American Statistician, 55, 19-24. Hoenig and Heisey show that so-called "observed power" is simply a re-expression of the p-value.
I hope this helps, John -------------------------------- John Fox, Professor Department of Sociology McMaster University Hamilton, Ontario, Canada L8S 4M4 905-525-9140x23604 http://socserv.mcmaster.ca/jfox > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > project.org] On Behalf Of Yuelin Li > Sent: April-08-08 12:47 PM > To: r-help@r-project.org > Subject: [R] post hoc statistical power > > I remember reading about post hoc statistical power on R-help. But I > can't seem to find them with RSiteSearch("post hoc statistical power") > and variations of it. > > I would like to learn more about post hoc statistical power, its > meaningfulness, advantages and disadvantages. I thought the issue was > settled after Tukey's 1993 paper about post hoc statistical power > being "essentially meaningless once the experiment has been done". > But they seem to be used, and sometimes encouraged > (e.g., http://www.informaworld.com/smpp/content~content=a787469931). > > I do not intend to start a debate. I simply would like to learn > more. Can anyone suggest a few articles? Thanks, > > Yuelin. > > Tukey JW. Tightening the clinical trial. Control Clin Trials. > 1993;14:266-285. > > > > ===================================================================== > > Please note that this e-mail and any files transmitted with it may > be > privileged, confidential, and protected from disclosure under > applicable law. If the reader of this message is not the intended > recipient, or an employee or agent responsible for delivering this > message to the intended recipient, you are hereby notified that > any > reading, dissemination, distribution, copying, or other use of > this > communication or any of its attachments is strictly prohibited. > If > you have received this communication in error, please notify the > sender immediately by replying to this message and deleting this > message, any attachments, and all copies and backups from your > computer. > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting- > guide.html > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.