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From |
Lloyd Dumont <lloyddumont@yahoo.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Intraclass Correlation for an Independent Variable? |

Date |
Thu, 12 Aug 2010 09:22:01 -0700 (PDT) |

Thank you for your advice on this, Steve. From a technical/statistical point-of-view, it was very helpful. I ran -loneway- on the dataset of individual workers. The F-stat was about 1.24, generating a p-value far greater than I would have wanted in order to please the reviewer--about .24. Given that, is there anything I can do to make the case for these measures? Is there a way to "correct for" the heterskedasticity of the estimated means for each plant before collapsing them into a dataset of plant-months? Off the top of my head, the first thing I thought of was to -collapse- the data using medians as opposed to means. That way, I could at least be assured that outliars are not influencing each plant's score. Interestingly, when I did that, the results in the regression of plant-months became a little stronger. Thank you again. Lloyd --- On Wed, 8/11/10, Steve Samuels <sjsamuels@gmail.com> wrote: > From: Steve Samuels <sjsamuels@gmail.com> > Subject: Re: st: Intraclass Correlation for an Independent Variable? > To: statalist@hsphsun2.harvard.edu > Date: Wednesday, August 11, 2010, 5:47 PM > I didn't read the second part of your > message closely enough. ICCs > can be computed for any variable measured in groups,and the > reviewer's > terminology is impeccable. -loneway- should do what > you want. But > "search intraclass, all" will find some extensions. > > Steve > > On Wed, Aug 11, 2010 at 5:05 PM, Steve Samuels <sjsamuels@gmail.com> > wrote: > > The reviewer could well want to know if the plant > differences in the X > > means are real. So, yes, he or she could really mean > "X". This is > > the kind of question you'd test with a one-way ANOVA, > or KW. You will > > need the data from the individual worker X > measurements, or the > > plant-specific sample sizes and variances. > > > > Steve > > On Wed, Aug 11, 2010 at 4:36 PM, Lloyd Dumont <lloyddumont@yahoo.com> > wrote: > >> 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 plant. > >> > >> 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/ > >> > > > > > > > > -- > > Steven Samuels > > sjsamuels@gmail.com > > 18 Cantine's Island > > Saugerties NY 12477 > > USA > > Voice: 845-246-0774 > > Fax: 206-202-4783 > > > > > > -- > Steven Samuels > sjsamuels@gmail.com > 18 Cantine's Island > Saugerties NY 12477 > USA > Voice: 845-246-0774 > Fax: 206-202-4783 > > * > * 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/

**Follow-Ups**:**Re: st: Intraclass Correlation for an Independent Variable?***From:*Steve Samuels <sjsamuels@gmail.com>

**References**:**Re: st: Intraclass Correlation for an Independent Variable?***From:*Steve Samuels <sjsamuels@gmail.com>

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