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.
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On Tue, 8 Apr 2008, Yuelin Li wrote:> 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,Start here: Hoenig, John M. and Heisey, Dennis M. (2001) The abuse of power: The pervasive fallacy of power calculations for data analysis The American Statistician, 55, 19-24 Keywords: bioequivalence testing; BURDEN OF PROOF; OBSERVED POWER; RETROSPECTIVE POWER ANALYSIS; statistical power; Type II error CISid: 222509 HTH, Chuck> > 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 at 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. >Charles C. Berry (858) 534-2098 Dept of Family/Preventive Medicine E mailto:cberry at tajo.ucsd.edu UC San Diego http://famprevmed.ucsd.edu/faculty/cberry/ La Jolla, San Diego 92093-0901
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: r-help-bounces at r-project.org [mailto:r-help-bounces at r- > project.org] On Behalf Of Yuelin Li > Sent: April-08-08 12:47 PM > To: r-help at 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 at 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.
Many thanks to John Fox and Charles C. Berry. Both point to the paper by Hoenig and Heisey (email from John Fox below):> 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.==================================================================== 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.