NBC-WSJ-Marist released the results of a new poll, in which respondents from Pennsylvania were asked for whom they will vote: Democrat candidate Hillary Clinton or Republican candidate Donald Trump.
NBC-WSJ-Marist poll results
The poll was carried out 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 race is currently a statistical tie.
Putting the results in context
Single polls can incorporate large errors, which is why they should be interpreted with caution. Rather, one should check how a poll's results compare to benchmark forecasts.
For the following comparison, we convert the candidates' raw poll numbers into two-party vote shares. The resulting figures are 43.5% for Clinton and 0.0% for Trump.
Comparison to other polls
Clinton can currently count on 44.8% of the two-party vote in an average of recent polls in Pennsylvania. This value is 1.3 percentage points higher than respective numbers in the NBC-WSJ-Marist poll. This deviation is within the poll's sampling error, which means that the poll is not an outlier.
The poll in comparison with PollyVote's forecast
The current PollyVote forecasts Clinton to gain 45.4% of the two-party vote in Pennsylvania. That is, Polly's forecast is 1.9 points above polling numbers. The PollyVote forecast is thus within the poll's error margin.