Thanks to everyone who spared some time to enlighten me on weighting issues. This list serve is undoubtedly a rich reservoir of knowledge. I now have enough info to assist me with weighting. Thanks once more.

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-----Original Message----- From: Tim Dunsworth <Tim.Dunsworth@METROSTATE.EDU> Newsgroups: bit.listserv.spssx-l To: SPSSX-L@LISTSERV.UGA.EDU <SPSSX-L@LISTSERV.UGA.EDU> Date: Wednesday, June 28, 2000 10:54 AM Subject: Re: Weight Determination (fwd)

>Yes, you're right Curt - it was a geezer lapse on my part that I didn't catch because my incorrectly computed weights still managed to preserve the total sample size (125 + 375 = 500, while the correct numbers are 100 + 400 = 500). Thanks for catching the error. > >>>> curtyboy@worldspy.net 06/27 6:39 PM >>> >see below > >> >> There are several types of weights in common use. Hector's reply uses one >definition that has the advantage that all statistics (eg. cumulative number >of cases up to some observed value of a numeric variable) are direct >estimates of the corresponding population values, but it has the >disadvantage of increasing the apparent sample size and thus affecting >significance values. >> >> If you want to preserve the same total sample size, calculate the weights >as the population proportion of each group divided by the sample proportion >of that same group. For urban dwellers that would be: >> W = (1000/4000) / (250/500) = 0.5 > >Tim: > >I'm trying to understand your recommendation. How do you define population >proportion? In this case, I would think that population proportion = >(1,000/5,000), and therefore the weight for urban dwellers would be: >(1000/5000)/ (250/500) = .4. > >And the weight for rural dwellers would be (4,000/5,000)/(250/500) = 1.6. > >Am I on or off target? > >Curt Dommeyer