How the poll was conducted

The Star Tribune Minnesota Poll findings are based on telephone interviews May 12 to May 15 with a representative sample of 1,203 adults in Minnesota telephone households, including 1,117 registered voters. Interviews were conducted under the direction of Princeton Survey Research Associates International (PSRAI).

Results of a poll based on 1,203 interviews will vary by no more than 3 percentage points, plus or minus, from the population 95 times out of 100. Margins are larger for groups within the sample.

The head-to-head election results for Norm Coleman against the DFL candidates are based on interviews with registered voters only and have a margin of error of 3.6 percentage points, plus or minus.

Sampling error does not take into account other sources of variation inherent in public opinion surveys such as nonresponse, question wording or context effects. In addition, news events may have affected opinion during the period the poll was taken.