Results of a new poll administered by NBC-WSJ-Marist were spread. The poll asked interviewees from Pennsylvania for whom they will vote: Hillary Clinton or Donald Trump.
NBC-WSJ-Marist poll results
According to the results, 48.0% of respondents said that they would vote for former New York Senator Hillary Clinton, while 37.0% said that they would vote for businessman Donald Trump.
The poll was conducted from August 3 to August 7 among 834 registered voters. There is a sampling error of +/-3.4 percentage points. Considering this error margin, the gap between both candidates is statistically significant.
Putting the results in context
As a general rule, however, you should not have too much faith in the results of single polls, as they sometimes contain large errors. Rather, one should examine how a poll's results compare to benchmark forecasts.
In order to make the results comparable to forecasts from other methods, you can convert them into shares of the two-party vote. The respective figures are 56.5% for Clinton and 43.5% for Trump.
Results in comparison to other polls
Clinton currently runs at 55.2% of the two-party vote in an average of recent polls in Pennsylvania. Relative to her numbers in the NBC-WSJ-Marist poll Clinton's poll average is 1.3 percentage points worse. This deviation is within the poll's margin of error, which suggests that the poll is not an outlier.
The poll compared with PollyVote's forecast
The most recent PollyVote forecasts Clinton to gain 54.6% of the two-party vote in Pennsylvania. That is, the combined PollyVote is 1.9 points below her polling numbers. Again, a look at the poll's error margin reveals that this deviation is insignificant.