The Simon Poll/SIUThe Simon Poll/SIU published the results of a new poll on October 24. In this poll, participants from Illinois were asked for whom they will vote: Democrat candidate Hillary Clinton or Republican candidate Donald Trump.
The Simon Poll/SIUThe Simon Poll/SIU poll results
Of those who answered the question, 53.0% said that they would vote for former First Lady Hillary Clinton, whereas 28.0% revealed that they would give their vote to businessman Donald Trump.
This poll was conducted from September 27 to October 2, among a random sample of 865 likely voters. If one takes into account the poll's margin of error of +/-3.3 percentage points, the difference between both candidates is statistically significant.
Putting the results in context
As a general rule, however, one should not have too much faith in the results of single polls, because they may incorporate large errors. Rather than relying on results from single polls, one should consult combined polls or, even better, a combined forecast that relies on different methods and data.
In order to make the results comparable to benchmark forecasts, one can translate them into two-party vote shares. This yields figures of 65.4% for Clinton and 34.6% for Trump.
Comparison to other polls
Clinton currently achieves 59.2% of the two-party vote according to an average of recent polls in Illinois. Relative to her numbers in the The Simon Poll/SIUThe Simon Poll/SIU poll Clinton's poll average is 6.2 percentage points lower. This difference is outside the poll's error margin, which suggests that the poll is an outlier.
Results compared to the combined PollyVote prediction
The most recent PollyVote predicts Clinton to gain 59.0% of the two-party vote in Illinois. This means that Polly's forecast is 6.4 points below her polling numbers. Again, a look at the poll's sampling error reveals that this difference is significant.