Q: I’ve seen some newspaper stories about your U.S. Religious Knowledge Survey. It seems that your categories include “Jews” and “atheists/agnostics.” Well, I’m BOTH Jewish and an atheist. Don’t you realize that there are people like me? How would you classify me?

Yes, lots of people have complex religious identities. We can’t account for every possible variation, but we’re able to track a wide variety of combinations — especially the more common ones — because we ask people not only about their primary religious affiliation but also about their specific beliefs and practices. This allows us to gauge, for example, how many people consider themselves Jewish but don’t believe in God; in the U.S. Religious Knowledge Survey, 15% of the Jewish respondents said they are non-believers.

How we would classify you, however, depends on exactly how you described yourself. First, we ask respondents about their religious affiliation. The full question wording is, “What is your present religion, if any? Are you Protestant, Roman Catholic, Mormon, Orthodox, such as Greek or Russian Orthodox, Jewish, Muslim, Buddhist, Hindu, atheist, agnostic, something else, or nothing in particular?” This measure is based wholly on self-identification: If you say that you are Jewish, we classify you as Jewish.

But that’s not the end of the story. For all those who name a particular religion, we follow up with questions about the specific denomination. We also ask Christians whether they consider themselves to be “born-again” or evangelical. We ask everyone — no matter what they’ve said in the religious affiliation question — how important religion is in their lives, how often they attend religious services and whether they believe in God or a universal spirit. For those who say they believe in God, we ask: “How certain are you about this belief? Are you absolutely certain, fairly certain, not too certain, or not at all certain?” In the Religious Knowledge Survey, as in many of our surveys, we also ask respondents about their views of the Bible and of evolution. And we ask about the religious affiliation of the respondent’s spouse or partner, if any.

Taken together, these questions allow people to express a rich diversity of religious identities. Not only, for example, are there Jews who say they do not believe in God, but we know from previous surveys that there are also self-described atheists who say they DO believe in God, agnostics who say they attend worship services every week, and many other combinations. When we report the results of a poll such as the Religious Knowledge Survey, however, we tend to stick to the larger groups and, following good survey research practices, we do not separately analyze and report results for groups that have very small numbers in our sample.

Alan Cooperman, Associate Director, Research, Pew Forum on Religion & Public Life

(Note: How much do you know about religion? Take the religious knowledge quiz to find out.)