Hi Rafael, Your method would underestimate the error associated with values derived from single specimens because those values would have the highest errors, not average errors. What I have done in such cases is to estimate an average standard deviation across species and use that average standard deviation as the standard error of the species with single specimens. I don't know of a formal description of this solution but it is mentioned in one of my papers: http://rspb.royalsocietypublishing.org/content/279/1733/1567
Best, Santiago Research Associate Department of Ornithology American Museum of Natural History https://sites.google.com/site/sclaramuntuy/ > On Aug 16, 2016, at 4:34 PM, Rafael S. Marcondes <raf.marcon...@gmail.com> > wrote: > > Hi all, > > I’m using OUwie to fit multi-optima OU models and I have a question about > incorporating measurement error into my analyses. > > I’m running my models with known measurement error (mserr=‘known’) and > using the standard error (std.error()) as an estimate of it, as recommended > by Ives et al (2007). However, for some (a minority) of my tips, I was only > able to measure 1 specimen, so I have no standard error for them. So I’m > not sure about how to deal with those. At first I thought about just > setting their measurement error as 0, but then I figured that would > introduce false confidence. So what I’m doing now is I’m setting > measurement error for those tips as the mean of the errors of all the tips > for which I did measure more than one specimen. I got that idea also from > Ives et al when they mention averaging the error across species (jn the > third-to-last paragraph), but that was in a different context. I can’t find > any references that report dealing with the same problem, even though I > assume it must not be an uncommon one. So I’m wondering if mine is really > the best way to do it and, or if anyone has alternative suggestions? > > i hope I’ve made my problem clear, and thanks in advance for any > suggestions. > > > *--* > *Rafael Sobral Marcondes* > > PhD Candidate (Systematics, Ecology and Evolution/Ornithology) > Museum of Natural Science <http://sites01.lsu.edu/wp/mns/> > Louisiana State University > 119 Foster Hall > Baton Rouge, LA 70803, USA > > Twitter: @rafmarcondes <https://twitter.com/rafmarcondes> > > [[alternative HTML version deleted]] > > _______________________________________________ > R-sig-phylo mailing list - R-sig-phylo@r-project.org > https://stat.ethz.ch/mailman/listinfo/r-sig-phylo > Searchable archive at http://www.mail-archive.com/r-sig-phylo@r-project.org/ _______________________________________________ R-sig-phylo mailing list - R-sig-phylo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-phylo Searchable archive at http://www.mail-archive.com/r-sig-phylo@r-project.org/
