Bookmark and Share

Notice: On March 31, it was announced that Statalist is moving from an email list to a forum. The old list will shut down on April 23, and its replacement, statalist.org is already up and running.


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

st: Intraclass Correlation for an Independent Variable?


From   Lloyd Dumont <lloyddumont@yahoo.com>
To   statalist@hsphsun2.harvard.edu
Subject   st: Intraclass Correlation for an Independent Variable?
Date   Wed, 11 Aug 2010 13:36:01 -0700 (PDT)

Hello.  I have gotten a confusing note from a reviewer, confusing in part because I think he/she is using the wrong terminology.


In a nutshell…

I am running a cross-sectional time series model (on a dataset of plant-months) of a continuous variable Y measured at the plant level where the focal, continuous independent variable is X.  X is also at the plant-level, but is time-constant.  X is formed by taking the mean level of X from all of the individual workers in each plant.

The reviewer suggests that I include some measure of within versus between plant variance in X.  This would bolster the case that there is a genuine difference across plants rather than average differences simply reflecting noise.  He/she then goes on to suggest I do this by reporting intraclass correlations (ICCs).

As far as I understand it, ICCs (or rho) describe the variance in Y, not X.  If I am right, then the reviewer did not mean ICC.

Rather, he/she wants me to go back to the dataset of individuals (not plant-months) and wants me to run some simple analysis to show that there is clustering of values for X by clinic.

Am I correctly understanding what the reviewer is asking for?  And, if so, what is the simplest way to demonstrate the sort of dependence he/she is hoping to see?

Thank you for your help.  Lloyd



      


*
*   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 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   Site index