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From |
Michael McCulloch <mm@pinestreetfoundation.org> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Re: R: Minimal Detectable Difference |

Date |
Tue, 5 Jun 2012 08:16:44 -0700 |

Lars, See the user-written SAMPLESIZE: "samplesize does everything that sampsi does but in addition allows multiple values for every numeric parameter e.g. the number of follow-up measurements. The resulting values for either power or sample size are plotted in a twoway graph." Sincerely, Michael McCulloch, LAc MPH PhD Pine Street Foundation 124 Pine St, San Anselmo, CA 94960-2674 tel: 415-407-1357 fax: 206-338-2391 email: mm@pinestreetfoundation.org On Jun 5, 2012, at 6:33 AM, William Buchanan wrote: > Hi Lars, > > It may not be Stata, but you could also take a look at G*Power. It's free and can be used to calculate various aspects of statistical power (e.g., required sample size to detect a given effect size, minimum detectable effect size, etc...). It doesn't calculate these sizes for SEM or MLM, but for most other models you can get quick and easy answers. > > - Billy > > Sent from my iPhone > > On Jun 5, 2012, at 5:41, Lars Folkestad <lfolkestad@health.sdu.dk> wrote: > >> That is what i ended up doing. But i hoped there was a nicer/smerter/more >> standardized way to do it. >> lars >> >> Den 05/06/12 14.06 skrev "carlo.lazzaro@tiscalinet.it" >> <carlo.lazzaro@tiscalinet.it>: >> >>> >>> >>> >>> Lars can probably simulate some scenarios with -sampsi-. I find this >>> approach particularly useful when the limited number of participants >>> available is due to budget constraints (as it is often the case, sadly). >>> Kindest Regards, >>> Carlo >>> >>> >>> -----Messaggio originale----- >>> Da: owner-statalist@hsphsun2.harvard.edu >>> [mailto:owner-statalist@hsphsun2.harvard.edu] Per conto di Lars Folkestad >>> Inviato: martedì 5 giugno 2012 13:39 >>> A: statalist@hsphsun2.harvard.edu >>> Oggetto: st: Minimal Detectable Difference >>> >>> Dear List >>> >>> This might be a bit more of a stats question than a stata question. >>> >>> I am about to do a cross sectional study comparing two groups regarding a >>> measured continous variable. >>> I know the the variance of the measurement. No one has ever investigated >>> these groups before using this or similar machines. For practical reasons >>> i >>> only have a limited number of participants available for this project. I >>> am >>> now wondering what the minimal detectable difference between the two >>> groups >>> are with the number of participants i have available. >>> >>> I will use a t-test (paired, seeing the two groups are matched) >>> >>> How do i calculate this using stata? >>> >>> lars >>> >>> * >>> * For searches and help try: >>> * http://www.stata.com/help.cgi?search >>> * http://www.stata.com/support/statalist/faq >>> * http://www.ats.ucla.edu/stat/stata/ >>> >> >> >> * >> * For searches and help try: >> * http://www.stata.com/help.cgi?search >> * http://www.stata.com/support/statalist/faq >> * http://www.ats.ucla.edu/stat/stata/ > > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/statalist/faq > * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**References**:**st: Re: R: Minimal Detectable Difference***From:*Lars Folkestad <lfolkestad@health.sdu.dk>

**Re: st: Re: R: Minimal Detectable Difference***From:*William Buchanan <william@williambuchanan.net>

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