For more than six months, 10 specially trained workers have gathered every weekday in an office on L Street in Washington, D.C. Their job: Read the morning papers, surf the Internet, watch a lot of television and listen to the radio.

They’re not Federal Communications Commission censors. Nor do they work for political parties or special interest groups. Instead, these people are tracking the news reports of the American MSM, the acronym nickname in press circles for the “mainstream media.” They’re trying to provide an empirical basis for understanding coverage patterns and priorities in an era of growing concern over the influence, economics and ethics of the press.

And they’re probably getting a little bored.

After looking at the data for half a year, the directors of the project — which is being run by the Project for Excellence in Journalism, an endeavor of the Pew Research Center funded by the non-profit Pew Charitable Trusts — are starting to identify some clear trends in Washington coverage. Namely, the MSM tends to cover the same things.

“The story lines that the media follow are fairly narrow,” the director of the project, Tom Rosenstiel, who formerly had the media beat at the Los Angeles Times, said in offering a preview of the initial findings, to be publicly released this week. “If you look at cable news and the morning shows, and to some extent the evening news, there are a handful of stories that tend to dominate.”

This is particularly true of congressional coverage. While the volume of stories touching Capitol Hill has been rising ever since the Democrats took control in January, much of the coverage is the same, Rosenstiel says. “You get beyond the debate over Iraq policy, the attorney general scandal and a few other things, and there really isn’t a lot of coverage of Congress,” he says. “There was coverage of the immigration debate for a few months, to an enormous exclusion of other issues.”

The rest of the congressional domestic agenda, including education, the environment and health care, has taken only about 1 percent of the print and broadcast news holes so far in 2007, the researchers found. That may be partly because of the shrinking Washington bureaus and the dwindling resources in print and network news in general, Rosenstiel speculates; reporters who used to dig for scoops are now being deployed to follow the pack.

Measuring that pack mentality has been the project’s News Coverage Index, in which story topics from 48 general-interest sources — from The New York Times to The Bakersfield Californian, the “CBS Evening News” to “Scarborough Country” — are entered daily into a database. The methodology and software took a year to develop. The group issues its findings weekly, along with analyses of trends and comparisons of coverage in different cross sections of the media.

So far, the meta-story, predictably, has been the Iraq War; its domination of the coverage subsided a bit after Memorial Day, when Congress lost a showdown with President Bush and voted to continue funding without strings attached, but it revived last month when Democrats reopened the withdrawal debate. The war claimed 14 percent of the overall news hole in the week beginning July 15 (which included the all-night Senate debate), 5 percentage points more than the No. 2 story, the presidential campaign.

Others who monitor the media say they see what the project sees: Coverage of Congress is up, but it’s mainly because of one story. “It’s overwhelmingly about Iraq,” said Andrew Tyndall, who has been monitoring nightly TV news broadcasts since 1987.

The narrowing of topics is particularly acute on radio, cable TV and morning network shows, Rosenstiel says. Those tend to seize on the same story — the Virginia Tech shootings, say, or conditions at Walter Reed hospital — then drop it when something “hotter” comes along, like Anna Nicole Smith’s death or Paris Hilton’s jailing.

But news Web sites are “probably the most diverse in terms of what they’re willing to feature or lead with,” Rosenstiel said. “That’s a surprise. . . . They may figure that people are going to hunt for what they want. They don’t have to dangle in front of the audience stories that they already think have water-cooler appeal.” Such sites are most likely to put international stories at the top of their displays — even the recent release of Bulgarian medics imprisoned in Libya for allegedly spreading HIV, the virus that causes AIDS.

Those varied Web offerings could be an answer to newspaper and TV executives wondering why their audiences are dwindling while online readership is up. Perhaps it’s because of the resurgence of “pack journalism” with a 21st century twist. “The new ‘pack journalism’ is not people literally looking over each other’s shoulders,” Rosenstiel says, “but watching each other and saying, ‘That’s what people are talking about. That’s what we need to focus on.’ ”

His researchers on L Street are getting paid to consume the news. The American public isn’t. That’s why the rest of the media might do well to take note that diversity of coverage is emerging as a selling point to the new generation of news consumers.

Elizabeth Wasserman is a Washington freelance writer. She can be reached at ewasserman@cq.com.