What's next in evening news? Stay tuned

America's three original network news shows face the same momentous choice at nearly the same time: Pass the torch to a new anchor who, each hopes, has the gravitas to hold viewers and win new ones, or break with a star-driven tradition developed back in television's Pleistocene era and try something different.

This moment of transition - brought on by the departures of Dan Rather at CBS and Tom Brokaw at NBC, and now Peter Jennings's decision to curtail appearances on ABC's news broadcasts - brings into stark relief some of the ongoing challenges for the networks. Even with established names behind their news desks, the networks have been losing audiences to 24-hour cable news, Internet sites, and other sources of instant headlines.

All that competition, say many media analysts, will eventually force networks to experiment with the content, style, and format of the evening news.

"It's a question not just of having a different anchor or even having a different stage set for the news, it's a question of changing their entire news organization," says Michael Griffin, a professor in media studies at Macalester College in St. Paul, Minn. "They are being forced to change by their waning influence."

What's hard to tell is whether that moment has arrived for the 6:30 p.m. broadcasts. For now, ABC correspondents Elizabeth Vargas and Charles Gibson are filling in for Mr. Jennings, recently diagnosed with lung cancer. At NBC, Brian Williams is easing into Mr. Brokaw's still-warm chair, while the chatty Bob Schieffer is holding the line as the world's most visible temp, as CBS mulls over its next step.

Part of the drop in audience share can be attributed to lifestyle changes of Americans. Longer hours at work and longer commutes have whittled away the number of people who are home to watch TV at 6:30. (Television's loss is radio's gain: NPR's "All Things Considered" now draws a sizable commuter crowd in search of news.)

More fundamental, though, is the fact that news travels extraordinarily fast in this time of media plurality. As a result, many TV watchers are already aware of the day's news by 6:30 and thus are more likely to watch reruns of "Seinfeld" instead.

The evening news format doesn't help matters either. Minus the ads, the average newscast is just 19 minutes, according to Andrew Tyndall, who analyzes the network news at The Tyndall Report. That time slot also lends itself to summarizing the day's events rather than providing the added value of in-depth reporting.

The evening news may be forced to compensate for those limitations by emphasizing news analysis, just as newspapers have done. Another possibility is to eliminate network news at 6:30 and replace it with an extended prime-time program that devotes 20 minutes to truncated news and the rest to a news magazine format, muses Mark Feldstein, a former correspondent for CNN and ABC News who worked for "Dateline" between 1998 and 2000.

"When I was at NBC, they talked about it with 'Dateline,' " recalls Mr. Feldstein, now director of the Journalism School of Media and Public Affairs at George Washington University. "The prime-time news magazines generally do better in the ratings at less cost, so that might be a way that the networks try to handle this."

Another strategy networks may need to adopt is to find a specialty or niche, as many local news shows have done. It's time the networks follow suit, argues Professor Griffin. He advocates that the UHF broadcasters leave the bulk of international reporting to the likes of CNN and Fox - which are in a better position to cover the world - to focus on domestic issues such as politics and finance.

One network is taking a novel step to stay relevant. Last Monday, ABC News announced that it will make its coverage available on a variety of media platforms. In addition to ABC News Now, a 24-hour news digital channel, it will provide broadband news and video on demand for cellphones and computers. "World News Tonight With Peter Jennings" is one of the products that will be accessible at any time. These steps should allow ABC to compete with cable news.

"If the reason why you're actually tuning into the 24-hour cable news network is because 'I want the news whenever I want it,' then the live format is actually inferior when you can get the news whenever you want it as video on demand," says Tyndall. Cable news is less tightly written, less comprehensive, and more difficult to digest than the sort of video packages ABC will offer, he believes.

Back on the regular airwaves, at least one network is expected to tinker with its anchor format. CBS may opt for multiple anchors.

It's been tried before, says Matt Welch, media columnist for Reason magazine, noting the disastrous combination of Connie Chung and Dan Rather and the multianchor format ABC briefly used in the late 1970s with Jennings and Frank Reynolds. A half-hour is too short for the audience to latch onto more than one personality, he says.

"Whatever brand loyalty there is, is based on the loyalty to the personality," says Mr. Welch, who'd like to see evening news employ a female anchor. "These things are made for single individuals."