Results of a new poll carried out by CBS News/YouGov were announced. The poll asked interviewees from Ohio for whom they will vote: Republican nominee Donald Trump or Democrat nominee Hillary Clinton.
In Ohio, the popular vote is often decided by a narrow margin. Therefore, the state is commonly referred to as a purple state, which makes it particularly interesting from a forecasting perspective.
CBS News/YouGov poll results
Of those who responded, 46.0% said that they will vote for former Secretary of State Hillary Clinton, whereas 39.0% indicated that they would give their vote to real estate developer Donald Trump.
The poll was conducted from September 7 to September 9 with 994 likely voters. The sampling error is +/-3.9 points. This means that the poll results for both parties' candidates differ significantly.
Putting the results in context
In general, however, you should not have too much faith in the results of single polls, since they often contain large errors. Instead of relying on results from single polls, you should consult combined polls or, even better, the combined PollyVote forecast that draws upon forecasts from different methods, each of which draws upon different data.
For the following comparison, we translate Trump's and Clinton's raw poll numbers into shares of the two-party vote. The resulting figures are 54.1% for Clinton and 45.9% for Trump. For comparison: Only 46.5% was gained by Clinton in the CBS News/YouGov poll on September 8, for Trump this number was only 0.0%.
Comparison to other polls
If we look at an average of Ohio polls, Clinton's two-party vote share is currently at 51.4%. This value is 2.7 percentage points lower than her respective numbers in the CBS News/YouGov 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 forecasts Clinton to gain 51.5% of the two-party vote in Ohio. That is, the combined PollyVote is 2.6 points below her polling numbers. Again, a look at the poll's margin of error shows that this difference is negligible.