Hello Forum, I have data for two groups of subjects for a ratio variable (cortisol level) assessed three times during the day (at 0600, 0900 and 2100 hours). So I have three means for each group. I have been asked to do a "slope analysis" to compare the two groups. According to my understanding, this means that I regress the three means on the time for each group and compare the slopes using a t-test (there is a post on this: Etienne Toffin etoffin at ulb.ac.be Tue Jan 27 20:08:36 CET 2009). My question: (if what I said is correct) it seems strange to me that we calculate a regression line with just three data points - is this really what is meant by a "slope analysis"?
Any help most appreciated... Ravi -- View this message in context: http://r.789695.n4.nabble.com/Help-with-slope-comparisons-tp3037455p3037455.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
