Political journalists give lavish attention to polls and often slide past those footnotes about a "95 percent level of confidence" and "margin of error plus or minus 4 percentage points."

Thus, numbers are never exact and a three-point edge could actually be seven points ahead or one point behind. Not to mention that even the best poll is merely a time-bound snapshot of reality (and it always pays to check how questions are worded).

After Election Day 2020, complaints about misleading political polls were as loud as usual, perhaps even louder. Take the bizarre Maine Senate race data. Polls consistently showed incumbent Susan Collins would lose, and she was behind 6% in the one closest to Election Day. She won easily by an 8.6% margin.

Or consider recent surveys about whether Americans plan to get COVID-19 shots. The Wall Street Journal notes that "yes" answers have ranged from 20% to 63% depending on the methodology, the wording and, especially, whether respondents were offered more than two options.

These days the "response rates" among those in randomly selected samples are so low it's tough to tell how representative the people are.

That's among the major problems raised by eminent Princeton sociologist Robert Wuthnow in his 2015 book "Inventing American Religion: Polls, Surveys, and the Tenuous Quest for a Nation's Faith.”

Gallup data about U.S. religion are important because the firm has asked consistent questions across so many decades. But 21st Century religion writers rely heavily upon the Pew Research Center (where Alan Cooperman, a former Washington Post colleague, is director of religion research). Pew's expertise often provides all-important distinctions between white "mainline" and white "evangelical" Protestants, and between white and Hispanic Catholics.

Pew is changing the way it surveys religious behavior and attitudes, so the media will want to be aware of why and how.

Of major importance is how this affects writing about trend lines over time that uses past surveys.