Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
| From | Maarten Buis <maartenlbuis@gmail.com> |
| To | statalist@hsphsun2.harvard.edu |
| Subject | Re: st: Using ksmirnov |
| Date | Wed, 5 Sep 2012 17:14:21 +0200 |
On Wed, Sep 5, 2012 at 4:41 PM, Morrison Hodges wrote: > I'm trying to use ksmirnov to compare 2 distributions to determine if there are any differences in the distribution of the variables. > > I have a .dta file with 179 patients. Each patient is classified as being in one of 7 groups from 1 to 7, i.e., group==1, group==2, etc. I want to compare the same variable between 2 groups. All variables are already sorted, from lowest to highest. For such a small sample size like that I would use Nick Cox's -stripplot- (see: -ssc desc stripplot-). The power of tests like -ksmirnov- is usually pretty bad, so in small sample sizes you are not going to find anything that is not glaringly obvious if you just looked at the data. On the other hand you will in all likelihood miss lots of real an interesting patterns if you focus on such low power tests. So, there is no added value to be got from these tests and a real chance of a loss. -- Maarten --------------------------------- Maarten L. Buis WZB Reichpietschufer 50 10785 Berlin Germany http://www.maartenbuis.nl --------------------------------- * * 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/