38 polling firms have polled one or more of the 36 Presidential Primaries and Caucuses to date in 2008.

Of them, 14 have polled 4 or more contests, and are designated as “active” election pollsters. Here’s a report card on the 14 most active 2008 election pollsters, ranked from smallest average error to largest average error (where smaller error is better, and zero is perfect). A separate, previous post, shows the same set of data for all 38 pollsters, not just the active ones.

Complete supporting detail, and caveats, on the jump …

Not all of the 14 most-active pollsters polled on the same contests or on the same number of contests. Some contests may have been harder to poll than others.

All information drawn from http://www.realclearpolitics.com/ , from http://www.pollster.com/ and, if disagreement on those two sites, from individual polling firm’s website. No polls or polling firms ere intentionally omitted.

Double-click on the following detailed table if you need to enlarge it to read it.

For a complete discussion of the different ways that election poll accuracy can be measured, including a summary of all 8 known measures, see this paper presented at the 2006 conference of the American Association for Public Opinion Research.

Super Tuesday election returns accurate as of 10 am ET on 02/06/08. In a couple of states, 100% of precincts had not yet reported.

Any errors in this table, or omissions from this table, should be reported to editor@surveyusa.com.

Update: PPP data corrected 020608 7:29 pm ET.