NEW YORK — Katie Couric isn't the only thing new at the "CBS Evening News."

Her first two weeks as anchor indicate that CBS is making some subtle but significant changes to a tradition-bound format, beyond the "Free Speech" commentary that has attracted the most attention since Couric's Sept. 5 debut.

At the bedrock is the assumption that many Americans no longer stay disconnected from the world through their workday and need a 22-minute summary on television to catch up.

Beyond the hiring of Couric, it's essential to shake things up at a broadcast that's been third in the ratings for years and part of an institution where all of the networks have been steadily losing viewers, said Sean McManus, CBS News president.

"If you are going to grow the audience, it's apparent that you're not going to grow the audience by doing the exact same things that have been done for years," he said.

The changes are most noticeable in the story count. While the third- and fourth-biggest stories of the day usually merit a correspondent's report on ABC and NBC, Couric will frequently breeze through a sentence or two and direct viewers to the CBS News Web site, CBSNews.com, for further details.

Besides "Free Speech," the time freed up is often devoted to an enterprise story, interview or backgrounder that's not necessarily tied to events of the day.

"What we're trying to do is dig a little deeper and maybe tell people some things that they may not have heard about," said Rome Hartman, the broadcast's executive producer.

The new direction was most obviously signaled when Couric led her very first broadcast not with breaking news, but a Lara Logan enterprise story on suicide attacks in Afghanistan. The decision looked sadly prescient when, three days later, a suicide car bomber attacked a U.S. military convoy in Kabul, killing 16 people.

The flip side is ignoring or kissing off a story that CBS' rivals deemed important to understanding what went on in the world that day.

CBS did nothing Tuesday, for example, on the reaction to President Bush's prime-time speech on terrorism the night before. McManus said he felt no new ground was broken, and the speech was adequately analyzed during the network's special report Monday night.

"If you're going to do something different, you have to occasionally be willing to not do something that the other two networks are doing," McManus said. "But if you've been No. 3 for 10 years, I'm not sure why you wouldn't do that. Putting on the exact same show the other two networks do every night would seem to be counterintuitive."

The first four nights of Couric's broadcast included 19 minutes of hard news, with the rest features, interviews and commentary, according to the Tyndall Report, which studies broadcast news content. By contrast, ABC's "World News" had 46 minutes of hard news, and NBC's "Nightly News" 44 minutes.

That's already led to whispers that CBS is now the "softer" newscast, somewhat ironic given that Couric predecessor Dan Rather for years used "hard news" as a mantra and a way to subtly tar his competitors.

McManus said it's a false impression: "We cover a lot of hard news and will continue to do so," he said. "I think adding perspective and taking a slightly different approach is also something worth trying."