>From: "David Conway" <[EMAIL PROTECTED]> >Don't call the kettle black (if you are a pot)!
You picked me, David! My wife's the stats teacher, not me. She gives you an 'F' for the phoney error calculation. :) As you say at the bottom, the sample must be representative of the population (only THEN would the population size not matter). With a self-selected sample, the only chance of useful information (well below the level of valid stastistical inference) is to have a very large sample. Ron's was tiny. That's why the GFA didn't amalgamate. With a voluntary vote, they still couldn't be sure about the opinion of the non-voting members. In your stats, they would have been justified in amalgamating because the probable 'error' was just over 4%. A self-selected sample is a biased sample and an 'error' calculation has no meaning. No valid inferences can be made from a bodgy sample about those not in the sample. You can make no valid inferences about all the pilots who DIDN'T vote (either for amalgamation or for an RPL). > >I think rational discussion is a better basis for decision making. I still prefer that to misleading statistics. :) Graeme Cant >From: "David Conway" <[EMAIL PROTECTED]> >Reply-To: [EMAIL PROTECTED] >To: <[EMAIL PROTECTED]> >Subject: RE: [aus-soaring] RPL results >Date: Fri, 21 Jun 2002 13:14:46 +0930 > >Don't call the kettle black (if you are a pot)! > >Actually the accuracy of the poll is independent of the total number of >glider pilots, but relates to the numbers in the poll itself. > >It doesn't matter if it's 31 out of 2000 or 31 out of 2 million > >The accuracy is given by 1 / Sqr Root (sample size) i.e. 1 / Sqr Root >31 = about 18% error which is a bit rough > >So Ron's results indicate, assuming a representative sample, that of >ALL the GFA members some 84% would be in favour - with an 18% error, so >even with the worst error would still have the majority in favour. > >Election-type polls typically involve only 1600 or so samples to give a >2.5% error, which is pretty good. > >And that 1600 samples is out of 10,000,000 voters (guess) that's only >0.016%, much less than Ron's 1.5% ratio > >The issue is, of course, are those 31 people who voted representative, >not that it is only 31 out of 2000 pilots. > > >David > > > > >-----Original Message----- > >From: [EMAIL PROTECTED] > >[mailto:[EMAIL PROTECTED]] On Behalf Of > >Graeme Cant > >Sent: Friday, 21 June 2002 1:57 AM > >To: [EMAIL PROTECTED] > >Subject: Re: [aus-soaring] RPL results > > > > > >>From: "Ronald E Baker" <[EMAIL PROTECTED]> > > > >>The results at 5pm EST stand at 5 no and 26 yes for a RPL, > >plus one who > >>thinks clubs should issue licenses! I think the situation is > >pretty clear > >>that a RPL should be the way to go. Cheers, Ron Baker. > > > >Give us a break, Ron. You're not that statistically > >illiterate! Your 31 > >voters are somewhere around 1.5% of glider pilots in this country. > > > >I'm tempted to run a poll on whether Ron's poll was a dopey idea. I'm > >pretty sure I'd get a majority that it was - largely from all > >those who > >disagree with Ron's obvious leaning. > > > >I think rational discussion is a better basis for decision making. > > > >Graeme Cant _________________________________________________________________ Chat with friends online, try MSN Messenger: http://messenger.msn.com -- * You are subscribed to the aus-soaring mailing list. * To Unsubscribe: send email to [EMAIL PROTECTED] * with "unsubscribe aus-soaring" in the body of the message * or with "help" in the body of the message for more information.
