Don't worry, there are plenty of halfwits around here. However, this is about stats theory, and not really about R, so you're better off trying CrossValidated, aka stats.stackexchange.com
-pd > On 24 Jan 2015, at 14:26 , Ben Brooker <awe....@googlemail.com> wrote: > > Hi, > > I am new to R and have not had the most exposure to statistics. > I have a dataset of percentage cover (so 0-100) for certain species in 3 > different shore zones (High, mid and low). The data was recorded for > different protected areas as well (17 of them) and my number of obs is > large (3358). I'm obviously interested in the difference in percentage > cover of species between shore zones as well as between protected areas. > The problem is that my data contains loads of zeros and I haven't dealt yet > in statistics with how to manipulate the data so as to perform robust tests > on it. I previously used Kruskal-Wallis ANOVAs to look at cover differences > in shore zone but I am worried that it is inappropriate because of the > large sample size that I have and because my variances are not equal. > > I've read a bit about using a zero-inflated negative binomial regression to > fit to my data, but I'm not sure if that will work because it is for count > data. > > I would very much appreciate it if someone could point me in the correct > direction wrt a transformation that may help or an appropriate model to fit > or test to use. I've searched quite a bit but I'm a out of my depth. > > PS sorry if I sound like a halfwit > > Thanks a lot > > Ben > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd....@cbs.dk Priv: pda...@gmail.com ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
