Bookmark and Share

Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: st: Computing effect size for a clustered randomized control trial


From   Scott Baldwin <[email protected]>
To   [email protected]
Subject   Re: st: Computing effect size for a clustered randomized control trial
Date   Mon, 3 May 2010 19:08:31 -0600

I'm not aware of any built in or user-written method in Stata for
computing power in cluster randomized trials. You can try the Optimal
Design software
(http://sitemaker.umich.edu/group-based/optimal_design_software) or
the formulae in David Murray's book "Design and analysis of group
randomized trials."

Best,
Scott


On Mon, May 3, 2010 at 5:23 PM, Joe McCrary <[email protected]> wrote:
> I am designing a randomized control trial, where we are going to
> select about 12 students per classroom and randomize them into 3
> groups, a control and 2 treatment groups. Is there a way I can compute
> the number of classrooms needed for the study using the following
> criteria:
>
> Desired power=0.8
> Estimated effect size = 0.2
> alpha = 0.0167
> 1 pre-test measure
> 1 post-test measure
> approx correlation between the two measures = 0.25
>
> --
> Joe McCrary
> Senior Research Associate
> WestEd-Atlanta
> 260 Peachtree St., Suite 2200
> Atlanta, GA 30303
>
> ph: 541-782-8626
> fax: 404-393-3797
>
> Skype: joe.mccrary
> Google talk; joe.mccrary
> **********************
>
> "No problem can be solved from the same level of consciousness that created it."
> --Albert Einstein
> *
> *   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/


© Copyright 1996–2018 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   Site index