Those interested in the problems with poll sampling should look at some of the political methodology research on the issue.
The most salient paper I know of is Gerber and Green's "Enough Already with Random Digit Dialing: Can Registration- Based Sampling Improve the Accuracy of Election Forecasts?": http://www.yale.edu/isps/publications/regsamp.pdf -- fh # distributed via <nettime>: no commercial use without permission # <nettime> is a moderated mailing list for net criticism, # collaborative text filtering and cultural politics of the nets # more info: [EMAIL PROTECTED] and "info nettime-l" in the msg body # archive: http://www.nettime.org contact: [EMAIL PROTECTED]