Hi Rick, Whenever I hear my instant association with post hoc and ANOVA would be ?TukeyHSD However, if you are not comfortable interpreting the model you ran, this suggests that you may benefit more from learning more statistical theory or finding someone to consult with who can help. You might also try graphing your data. Something like this would be one (of very many and not necessarily the best for your data) option:
library(lattice) xyplot(catchrate ~ habitat | site, data = pat) xyplot(catchrate ~ site | Gear, data = pat) xyplot(catchrate ~ habitat | Gear, data = pat) I tend to prefer using regression and then either accepting the default contrasts or (if I have some theory/hypothesis) specifying my own contrast matrices and using those. However, it is not really feasible for members of this list to help you interpret your results or suggest appropriate statistical techniques without knowing your actual data. If you have specific questions related to R (e.g., "How can I calculate <some test or statistic>? Here is a representative, but small sample dataset."), you will get a lot more advice and help. Best regards, Josh On Thu, Oct 21, 2010 at 4:13 PM, mirick <miri...@yahoo.com> wrote: > > Hello all, > Can any of you R gurus help me out? I’m not all that great at stats to > begin with, and I’m also learning the R ropes (former SAS user). > Here’s what I need help with… I have a nested sample design and ran a > nested anova, but I don’t know how to interpret the results > habitat (four different types) is nested in site (three types), and site is > nested in gear (two types) > My code: pat2<-aov(catchrate~habitat/site/gear, data=pat) > This created the following outcome: > Df Sum Sq Mean Sq > F value Pr(>F) > habitat 3 2.932 0.9774 > 0.9543 0.4155656 > habitat:site 8 18.716 2.3395 > 2.2842 0.0235207 > habitat:site:Gear 12 39.244 3.2704 > 3.1930 0.0003546 > Residuals 186 190.505 1.0242 > > What exactly does this outcome mean? It looks like there are differences > between gears and sites, but not among habitats. Which gear is better, > which site is better, which gear works better in each site, etc.? > I’ve looked for some post hoc code to do this, but I can’t find anything and > I am at wits end. > Thanks, > Rick M. > > -- > View this message in context: > http://r.789695.n4.nabble.com/nested-anova-tp3006469p3006469.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. > -- Joshua Wiley Ph.D. Student, Health Psychology University of California, Los Angeles http://www.joshuawiley.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.