Reading the polls? Keep the grains of salt handy

Poll watchers sometimes obsess over small differences in topline numbers, even those within a poll’s reported margin of sampling error.

But those differences pale in comparison to the size of the differences noted above. For those living in a world which hangs on every 1- or 2-point shift in the polls, the range of results is jarring.

To pollsters, though, the variation isn’t all that unexpected, or alarming.

“It’s a bathroom scale, not a kitchen scale,” says Cliff Zukin, a professor emeritus at Rutgers University who wrote a guide to variance in polls for the American Association for Public Opinion Research ahead of the 2016 election. “It’s pretty good at measuring pounds, but it’s not good at ounces.”

CNN.com, August 20, 2020