NBC/SurveyMonkey released the results of a new national poll, in which respondents were asked for whom they will vote: Republican nominee Donald Trump or Democrat nominee Hillary Clinton.
NBC/SurveyMonkey poll results
The Internet poll was conducted between August 15 and August 21. The sample size was 17459 participants. There is a sampling error of +/-0.8 percentage points. Considering this error margin, the gap between both candidates is statistically significant.
Putting the results in context
Single polls may incorporate substantial biases, which is why they should be treated with caution. At the very least, one should check how a poll's results compare to benchmark forecasts.
In order to make the results comparable to forecasts from other methods, one can translate them into two-party vote shares. This procedure yields figures of 45.7% for Clinton and 54.4% for Trump. In the latest NBC/SurveyMonkey poll on August 3 Clinton obtained 54.4%, while Trump obtained only 45.7%.
Comparison to other polls
An average of recent polls has Trump at 47.0% of the two-party vote. Relative to numbers in the NBC/SurveyMonkey poll Trump's poll average is 7.4 percentage points worse. This difference is outside the poll's sampling error, which suggests that the poll is an outlier.
Comparison to the combined PollyVote
The latest PollyVote forecasts Trump to gain 46.5% of the two-party vote. That is, the combined PollyVote is 7.9 points below polling numbers. Again, a look at the poll's sampling error reveals that this deviation is significant.