The margin of error, the plus or minus 3% in the above example, decreases as the sample size increases. This is only to a point. A very small sample, such as 50 respondents, has about a 14 % ...

Even poll-savvy people sometimes misrepresent the margin: After the 2016 election, one political scientist wrote an article about polling lapses for The Conversation, a portal for writing by ...

As the director of the Quinnipiac University Poll, which has been taking the pulse of the public on policy issues and elections for the past 30 years, I’ve noted that people have been paying ...

A version of this article appears in print on , Section A, Page 2 of the New York edition with the headline: Where Polls Can Mess Up (and How to Fix It). Order Reprints | Today’s Paper | Subscribe ...

Conversely, larger samples can reduce the margin of error, improving the precision of the measure. More on polls: How to tell if a political poll is skewed.