The three major television networks this week established bureaus in the opening caucus state of Iowa, officially launching their 1988 presidential campaign. It will be a new kind of campaign for the austerity-prone network news divisions, based on the principle that less is more.

"It's no longer practical or really feasible to cover candidates in the traditional way of putting producers, correspondents and camera crews on every campaign," said CBS politics producer Richard M. Cohen. "This is an era of diminished resources."

"The reality of the industry today is that it's on a plateau," said ABC News vice president Robert Murphy. "We do not have unlimited funds. We have to operate within a fairly controlled budget."

By one estimate, each network will spend about $25 million, about half of what such coverage would have cost under the lavish standards of the past. But the networks argue that the news won't suffer and that viewers won't be less informed. Rather, the political reporting will be more "interpretive" and more "analytical," they say, and there will be just as much of it as before.

"I'm quite confident that financial restriction will not get in the way of good coverage," said executive producer Bill Wheatley of the "NBC Nightly News." And NBC News senior vice president Joe Angotti said, "Despite what everybody is saying, the amount of money I have available is about the same as I had in 1984," a number that he refused to disclose.

The networks have decided, initially at least, to employ a "zone" instead of the traditional "man-to-man" system of coverage. An off-air reporter is assigned to each of the seven Democratic and six Republican presidential candidates, but not the camera crew, correspondent and field producer who were de rigueur in campaigns past. Instead, teams based in Iowa and New Hampshire will intercept the candidates on the ground, and the networks will depend more than ever on footage from affiliate stations.

"The ability to rely on our affiliates for technical and editorial support is much different this time than before," said ABC's Murphy, citing improved technical skills and reporting.

Meanwhile, off-air reporters, said Cohen of CBS, "will be our eyes and ears, and, if something newsworthy happens, we will know it and get the tape from the affiliate. Of course, there is a risk that we're going to miss stuff."

That risk is very real. On Tuesday night's news programs, only ABC had footage of Sen. Robert J. Dole (R-Kan.) in New Hampshire, reacting to an attack from Vice President Bush. The other two networks, which had no crews with the senator, made do with a written statement from the Dole campaign.

"If there's no CBS affiliate or other friendly camera there, we're out of luck," Cohen said. "And if that happens too much, we're going to have to rethink what we're doing."

Still, Cohen and others see advantages to the new information order. "There will be far less formula campaign-stop coverage," he said. "We'll look much more at points of vulnerability of all the candidates on an issues level. I think we're going to try and impose our agenda on the coverage by dealing with issues and subjects that we choose to deal with instead of parroting the candidates."

Hal Bruno, director of political coverage for ABC, said there will no longer be a financial motive to put a candidate on the air. "There are so many people involved, we almost had to get stories on, even though they're not newsworthy," he said. "It's a compulsion: 'So-and-so hasn't been on for a week, so let's get him and his candidate on.' "

The campaigns are sorting through the implications of the network strategy. "We can't figure out if it's better or worse than times gone by," said John Buckley, press secretary to Rep. Jack Kemp (R-N.Y).

But one campaign staff member, who asked not to be identified, lamented the demise of "the boys-on-the-bus factor."

"When reporters are assigned full-time to a campaign, they tend to treat you better," the staffer said. "Their success is hung on your star. They're people you go out with on the trail. And they're often kinder to you in their coverage. If they're doing zone coverage, that collegial atmosphere is diminished. They may be more objective -- which is bad for us."