How the poll was conducted

Today's Star Tribune Minnesota Poll findings are based on interviews conducted Sept. 12-14 with 625 Minnesota registered voters who say they are likely to vote in the presidential election. The interviews were conducted via landline (69 percent) and cellphone (31 percent). The poll was conducted by Mason-Dixon Polling and Research Inc.

Results of a poll based on 625 interviews will vary by no more than 4.0 percentage points, plus or minus, from the overall population 95 times out of 100. Margins are larger for groups within the sample, such as Democrats and Republicans, and income groups.

The self-identified party affiliation of the respondents is 37 percent Democrats, 29 percent Republicans and 34 percent independents or other.

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 opinions during the period the poll was taken.

Readers can e-mail questions to djmcgrath@startribune.com.