Poll Accuracy facts & stats

Question 1

A subgroup with about 160 respondents has roughly what margin of error for a single candidate?

Accepted Answer

about ±8 points. For the gap between two candidates within that subgroup, the margin is about ±16 points.

Question 2

Of 590 national polls in 2012, about how many would be expected to fall outside their margin of error by chance alone?

Accepted Answer

about 5% (roughly 30). A shift from a 5-point to an 8-point lead carries a ±8-point margin of its own.

Question 3

In 2024, what was the average absolute error of 611 pre-election polls in their final two weeks?

Accepted Answer

3.3 points. That was down from 5.3 points in 2020 and 5.2 in 2016.

Question 4

By how many points, on average, did 2024 national presidential polls miss?

Accepted Answer

2.6 points. State-level presidential polls missed by 3.0 points on average.

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