Points facts & stats

Question 1

By 2018, what share of people that pollsters called actually completed a phone survey?

Accepted Answer

about 6%. Response rates for phone surveys had fallen dramatically, even though pollsters could still get accurate results from smaller samples.

Question 2

For a typical opinion poll of about 1,000 people, what margin of error does that sample size usually produce?

Accepted Answer

about plus or minus 3%. A sample of roughly 1,000 people is the standard size behind most national polls you see reported in the news.

Question 3

To shrink a poll's margin of error down to about 1%, roughly how many people need to be surveyed?

Accepted Answer

about 10,000. Cutting a poll's margin of error by two-thirds takes a much bigger sample, which is why most polls settle for about 3% instead.

Question 4

When Singapore began using early 'sample count' results on election night, what margin of error did officials cite?

Accepted Answer

about 4%. Singapore's election-night sample counts, drawn from partial ballots, are designed to give a fairly accurate early read.

The basics