Results of a new poll conducted by Suffolk University were announced. The poll asked interviewees from Ohio for whom they will vote: Hillary Clinton or Donald Trump.
Ohio is traditionally a battleground state, where the Democrats and the GOP have often won similar levels of voter support. This is why the election outcome here is viewed as important in determining which party will win the majority of electoral votes.
Suffolk University poll results
The results show that both candidates have equal levels of support, each with 44.0% of the vote.
The poll was carried out from July 18 to July 20 among 500 likely voters. The margin of error is +/-4.4 percentage points, which means that the poll results for Trump and Clinton do not differ significantly.
Putting the results in context
As a general rule, however, a good strategy is to not have too much faith in the results of single polls, because they may incorporate large errors. Instead of trusting the results from single polls, the best practice scientific advice is to look at combined polls or, even better, a combined forecast that includes forecasts from different methods, each of which includes different data.
To make the results comparable to forecasts from other methods, one can convert them into two-party vote shares. The results of the actual poll mean 50.0 % for Clinton and 50.0 % for Trump in the two-party vote share.
Comparison to other polls
In comparison to the average results of other polls Clinton performed worse with 0.5 percentage points, while Trump did better with 0.5 percentage points. This difference is outside the poll's sampling error, which suggests that the poll is an outlier.
Comparison to the combined PollyVote
The most recent PollyVote predicts Clinton to gain 50.7% and Trump 49.3% of the two-party vote in Ohio. Clinton has 0.7 percentage points less and Trump has 0.7 percentage points more when the results of the poll are compared to the combined PollyVote forecast for Ohio. Again, a look at the poll's error margin indicates that this difference is significant.