David Winsemius wrote: > I am having difficulty thinking that you cannot find general material by > doing a Google search, but can tell you from memory that the US National > Center for Health Statistics publishes on the WWW quite a bit of > information about their survey methods. > > For an R-centric answer: Have you looked at the survey package that > Lumley created? > > Doing help.search("sampling") I also see that wtd.mean is available in > Harrell's Hmisc. The help page for that function also has useful links.
However, be very careful to note that there are - frequency weights ("I have n of these") - variance weights ("This is (like) the average of n obs") - sampling weights ("In reality, there are n times more of these") and the formula for the weighted mean may be the same, but those of the SD or the SEM are quite different. -pd > > --David Winsemius > > On Nov 24, 2008, at 3:34 PM, Robert Wilkins wrote: > >> Hi, >> >> Where can I find information ( freely available on the Internet , and >> also >> books or other sources ) on how having sampling weights changes the >> calculation of the standard error (of means and proportions)? >> >> How good is R for this type of procedure? And SAS? >> >> thanks >> >> Robert >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> 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. > > ______________________________________________ > 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. -- O__ ---- Peter Dalgaard Ă˜ster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 ______________________________________________ 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.