In just about any discussion of a poll about the very close presidential race between Vice President Kamala Harris and former President Donald Trump, you’ll hear ...

Notice that increasing the size of the sample eventually leads to diminishing returns of increased precision. That is why most polls include either around 600 respondents or around 1,000 respondents.

In just about any discussion of a poll about the very close presidential race between Vice President Kamala Harris and former President Donald Trump, you'll hear the ...

In presidential elections, even the smallest changes in horse-race poll results seem to become imbued with deep meaning. But they are often overstated. Pollsters ...

I am a statistician, and part of my job is to make inferences and predictions. With unlimited time and money, I could simply test or survey the entire group of people I am interested in to evaluate ...

Andrew Gelman, a professor in the departments of statistics and political science at Columbia University, explains. A "3 percent margin of error" means that there is a 95 percent chance that the ...