The record of internet-based opinion polls in predicting the results of 72races in the November 2000 US elections

The authors describe the use of internet-based surveys to predict the resul ts of 72 races in the US elections of November 2000. The authors describe t heir results, the methods they used, including the use of both demographic and 'propensity score' weighting to correct for substantial biases in the r aw, unweighted data, and the investments which were needed to achieve these results. They also caution readers not to assume that identical methods ca n be used with equal success in other countries or to measure all other var iables, and stress the need for continuing research to improve online resea rch methods in the future.