Thursday, 11 September 2003

More polling

Daniel Drezner has the scoop on a poll of Californians conducted by Knowledge Networks on behalf of Stanford University’s Hoover Institution from August 28 through September 8 that finds Arnold Schwarzenegger in a commanding lead and the recall with 62% support, contrary to many polls that show Bustamante in the lead and the recall question in a dead heat. One possible explanation for the difference:

The Stanford/Knowledge Networks survey is the first to ask voters to choose from the same list of 135 candidates that they will see on election day. Previous polls have restricted voters’ choices to the top candidates and have allowed respondents to select “undecided” or similar options.

If this methodological difference alone* makes that large a shift in the results—and there is fairly good reason to believe that it does—then there’s good reason to believe that the existing polling is flawed, since this methodology more accurately reflects the balloting environment.

Meanwhile, SacBee columnist Daniel Weintraub thinks a Schwarzennegger-McClintock detente may be in the offing.

Robert of Boomshock has some thoughts on the meaning of the poll as well. As for Knowledge Networks’ methodology, I recommend this page which explains how their panel works; it's pretty dissimilar from Harris Interactive’s approach. KN in general has some pretty smart people on board (as, for that matter, does HI) who’ve put a lot of thought in how to make Internet-based surveys representative.

* There are other possible explanations for the difference; for example, it could be simply the result of random chance (hence why pollsters attach 95% confidence intervals to these estimates) or it could be the result of different compositions of the WebTV-based Knowledge Networks panel and the set of Californians who respond to telephone surveys. On the latter point, the only independent comparison I’ve seen between Knowledge Networks’ methodology and telephone polling (RDD) shows the two to provide roughly equivalent estimates of population parameters (Harris Interactive’s propensity-weighting system for its opt-in Internet-based system, however, seemed to outperform both RDD and Knowledge Networks).