Quinnipiac published the results of a new poll on August 1. In this poll, respondents from Pennsylvania were asked for whom they will vote: Republican Donald Trump or Democrat Hillary Clinton.
Quinnipiac poll results
Of those who responded, 41.0% said that they will vote for former First Lady Hillary Clinton, while 43.0% declared that they would give their vote to real estate developer Donald Trump.
The poll was carried out from June 30 to July 11 among 982 registered voters. Considering the poll's error margin of +/-3.1 percentage points, the results reflect a statistical tie.
Putting the results in context
Single polls should be regarded with caution, as they may include substantial biases. Instead of trusting the results from single polls, the best practice is to consult combined polls or, even better, the combined PollyVote forecast that includes forecasts from different methods, each of which includes different data.
For the following comparison, we convert the candidates' raw poll numbers into shares of the two-party vote. This yields figures of 48.8% for Clinton and 51.2% for Trump.
Results in comparison to other polls
If we look at an average of Pennsylvania polls, Trump's current two-party vote share is at 47.5%. In comparison to his numbers in the Quinnipiac poll Trump's poll average is 3.7 percentage points lower. This difference is outside the poll's sampling error, which means that the poll is an outlier.
The poll compared with PollyVote's prediction
The latest PollyVote forecasts Trump to gain 47.4% of the two-party vote in Pennsylvania. Hence, Polly's forecast is 3.8 points below his polling numbers. Again, a look at the poll's sampling error suggests that this difference is significant.