Results of a new poll administered by Marquette were spread. The poll asked participants from Wisconsin for whom they will vote: Hillary Clinton or Donald Trump.
Marquette poll results
The results show that 46.0% of participants intend to vote for former New York Senator Hillary Clinton, while 42.0% plan to vote for real estate developer Donald Trump.
The poll was conducted from October 6 to October 9 among 878 likely voters. There is a sampling error of +/-3.9 percentage points. Considering this error margin, the race is currently a statistical tie.
Putting the results in context
As any other method, polls are subject to bias. In general, a good strategy is to not put too much trust in the results of a single poll. Instead of relying on results from single polls, you should look at combined polls or, even better, a combined forecast that draws upon different methods and data.
For the following analysis, we translate Clinton's and Trump's raw poll numbers into two-party vote shares. This procedure yields figures of 52.3% for Clinton and 47.7% for Trump. In the most recent Marquette poll on March 28 Clinton obtained 56.0%, while Trump obtained only 44.1%.
Results vs. other polls
If we look at an average of Wisconsin polls, Clinton's current two-party vote share is at 53.6%. This value is 1.3 percentage points higher than her respective numbers in the Marquette poll. This deviation is within the poll's sampling error, which suggests that the poll is not an outlier.
The poll in comparison with PollyVote's forecast
The current PollyVote expects Clinton to gain 51.9% of the two-party vote in Wisconsin. That is, the PollyVote forecast is 0.4 points below her polling numbers. Again, a look at the poll's margin of error indicates that this deviation is negligible.