Four years after the biggest embarrassment in the history of television news, network executives are vowing to do better on Nov. 2.

"No one wants a repeat of what happened, when we became part of the story of election night," said NBC News Vice President Bill Wheatley.

"We all learned a lesson four years ago," said Fox News Senior Vice President John Moody. "There will probably be an abundance of caution in most newsrooms, at least in ours."

What ABC, CBS, NBC, CNN and Fox did, as anyone who was watching well remembers, was to project an Al Gore victory in Florida on the basis of exit polls, and then to award Florida -- and the presidency -- to George W. Bush six hours later. But the race was so agonizingly close that it triggered a 36-day recount battle, and the news division presidents later apologized at a House hearing.

After the fiasco -- and a complete meltdown in exit polling for the 2002 election -- the five networks and the Associated Press dissolved their exit poll consortium, Voter News Service. They have hired two firms -- Edison Media Research and Mitofsky International -- to handle this year's surveys, and have turned over the actual vote-counting to the AP.

On election night, Edison's Joe Lenski and partner Warren Mitofsky will pore over the data in a third-floor office above a former Woolworth's store in Somerville, N.J.

Every Thursday since the Fourth of July, they have been running "stress tests" on their upgraded computer equipment, simulating the battlefield conditions of a 50-state election in the space of five hours. Not only has the system -- part of what insiders say is a $10 million operation -- functioned well, Lenski said, but all went smoothly during 23 primary contests.

"A lot of stuff worked in the spring, and that gives you more confidence going into November," Lenski said.

Although Lenski and Mitofsky, both highly regarded veterans who have done polling for CBS and CNN, will make recommendations about calling states, each news organization will make its own decisions.

For the first time, network executives vow they will not make projections in any state until all the polls have closed there. In 2000, the networks made their initial Florida projections while some voting was still taking place in the portion of the state on Central time, sparking complaints that they were influencing the voting.

In a fiercely competitive business, the biggest transformation seems to involve attitude.

"We're not going to make a projection until we're confident, and in some cases we may be slower, and that's the way it goes," said Dan Merkle, director of ABC's decision desk.

"It would be silly to say that what happened four years ago is not fresh in our minds four years later," said Tom Hannon, CNN's political director. "That's going to guide us in terms of prudence, caution and extreme diligence."

CBS News Vice President Linda Mason said anchor Dan Rather and news division president Andrew Heyward have made it clear that accuracy is more important than speed. During the Wisconsin primary, she said, the network was last to project a victory for Sen. John F. Kerry (D-Mass.). "Others were making predictions without returns from Milwaukee and Madison, and I refused to do that," Mason said. "Nobody questioned us: 'Why don't we have it?' "

CBS has moved its decision desk into the newsroom and assigned a correspondent, Mika Brzezinski, to explain to viewers how the exit polls are being used. Graphics will prominently feature the word "ESTIMATED" when states are called. "Our mantra is to be transparent," Mason said.

The number of exit polls on Nov. 2 will be roughly the same as four years ago, with about 2,000 voters being questioned in a key state. But projections can be thrown off by the growing trend toward absentee voting. Lenski and Mitofsky have ordered telephone polls in 13 key states, including Florida, to screen for absentee voters, and those surveys will begin as much as a week before Election Day. Only three such surveys were done in 2000.

This was a crucial issue in the televised fiasco four years ago. An internal investigation by Voter News Service found that the organization had no reliable way of estimating the number of absentee ballots in Florida, which were almost double what it had expected. The news service also dramatically underestimated the number of Florida votes that remained uncounted at 2 a.m.

This year, Lenski said, absentee ballots are expected to account for as much as 20 percent of Florida votes, rising to an estimated 50 percent in New Mexico and Colorado and 70 percent in Washington state. Any formula that does not adequately account for these early voters could be a prescription for disaster.

The quality-control system in 2000 was so poor that the media consortium failed to reject an early report that 95 percent of Florida's Duval County had voted for Gore. This time, Lenski said, if the numbers do not appear to match historical patterns, "big red flags are going to go up."

Fox, whose decision desk was then headed by John Ellis, President Bush's first cousin, was the first to call the race for Bush, and the other networks followed suit within four minutes. Network officials insist they will not be stampeded this time.

"I don't think there's any shame, if someone else is calling the race, in waiting to make sure you are absolutely right," Wheatley said.

Not that all traces of nervousness have been banished. "Are we 100 percent sure? Nothing is 100 percent," Fox's Moody said. "But we feel better about it, going into this one."

Howard Kurtz hosts CNN's weekly media program.