Then the researchers did what researchers do _ the math. The numbers suggested that there might be 1,969,000 or so Muslims linked to U.S. mosques in 2000. But there was a problem. Another study found 2,000 "mosques, schools and Islamic centers" and yet another 3,000, including "prayer locations." These numbers would push the population total higher. And what about all the Americanized, "cultural" Muslims who don't go to worship? What about mosques that only count the men?
"The data we have on how many people are going to mosques is actually pretty good, I believe," according to Mohamed Nimer of the Council on American-Islamic Relations. "The problem is what happens when you try to postulate up from that number to some kind of estimate for the total Muslim population in this country. "At that point, all kinds of things can happen to the numbers. No one agrees on how to make that leap."
This is serious business in the tense, highly politicized atmosphere following Sept. 11, 2001. Muslim leaders are striving to portray their community as a solidly mainstream presence in American culture. Everyone knows Islam is winning converts and becoming more visible, especially during seasons such as Ramadan, which is expected to end Dec. 6.
But how many Muslims are there in America? The Glenmary Research Center says 1.6 million, while CAIR and other Muslim advocacy groups say 7 million. Other reports jump all over the statistical map. Meanwhile, U.S. Census officials cannot ask questions about religion.
Writing in Public Opinion Quarterly, researcher Tom W. Smith is blunt: "None of the 23 specific estimates during the past five years is based on a scientifically sound or explicit methodology as far as one can tell from the published reports. All can probably be characterized as guesses or assertions." He concludes that the best estimates fall between 1.9 and 2.8 million, while most media reports continue to say 6 to 7 million.
While some researchers begin with data from mosques, others use telephone surveys. But Nimer said this fails to take into account immigrants whose English is weak. Others may hesitate to talk about their faith with strangers on the telephone. Finally, other surveys turn to immigration data focusing on ancestry and country of origin.
But immigrants are often hard to count, said journalist Joyce Davis, author of "Between Jihad and Salaam." Some are constantly moving to visit relatives in different parts of the nation, seeking the right place to settle. Some are unsure of their status with authorities. Some are trying to blend into this new culture. "A significant number of Muslims simply do not want people to be able to trace them through a mosque," she said. "This was true before 9/11 and it certainly is true now. The assumption is that the FBI is paying close attention to those membership lists. Many Muslims--for a variety of reasons--may not want to join anything right now."
There are layers of other complications. Nimer is convinced only one out of three U.S. Muslims actively practices his or her faith. It's hard to know precisely how many African Americans are converting. Some surveys are notorious for missing Muslims from Southeast Asia, where Indonesia has the world's largest Muslim population.
There is no clear bottom line. But Nimer said he believes conservative estimates of Muslims in America should fall between 2.5 and 4 million. "It is crucial to realize that this is an issue that applies to all religious groups, not just Muslims," he said. "It is hard, as a rule, to count religious people. ... Are you counting people who are born into a particular faith or those who practice it? Do you want to count Arabs or do you want to count Muslims? Or do you want to count Arabs who are Muslims?"