A Media Vow of Election Night Restraint Despite Social Media Clamor This has been the year of the big media gaffe. NBC News edited a 911 tape of George Zimmerman in a way that implied race as a factor in the Trayvon Martin shooting. CNN and Fox News falsely reported that the Supreme Court had struck down the individual mandate at the heart of the Obama administration's health care law. ABC News wrongly suggested a link between a mass shooting in Colorado and the Tea Party. Just last week during the storm, CNN repeated a false rumor about flooding at the New York Stock Exchange. Now the media are gearing up for election night, the finale of the year's biggest story. It's a chance to regain some credibility - presuming, of course, that television networks and other news organizations get their state-by-state projections right. They all say they will, still mindful of the mistakes made in 2000, when the networks prematurely called Florida for Al Gore and then George W. Bush. The same precautions that were put in place after 2000 will be in place again this Tuesday. At NBC, for instance, the statisticians at the "decision desk" that makes projections "are literally sealed off from the rest of us," said Mark Lukasiewicz, the senior vice president of specials for NBC News. Different this time will be the level of noise on the Web, where armchair and professional pundits alike will react to the election results in real time. On election night in 2008, a few Web sites, including Slate and Time.com, stated the obvious - that Barack Obama was going to win the presidency - well before the TV networks and major newspapers said so. In large part that's because the networks and newspapers were waiting for the polls to close on the West Coast. They will abide by the same principle again on Tuesday night, ruling out any such pronouncement before 11 p.m. Eastern. But more Web sites and individual users will most likely try to call the race early, creating a cacophony on social networking sites like Facebook and Twitter. A memo on Saturday to employees of The Associated Press, the country's biggest news wire service, asked them to refrain from adding to the noise by posting to Twitter about other news outlets" calls. "If A.P. has not called a particular state or race, it's because we have specifically decided not to, based on the expertise and data we have spent years developing," the memo read. In calling a state for Mr. Obama or Mitt Romney, news organizations will consider several data sources, including exit poll results and raw vote totals - "a brain trust of data," said Ingrid Ciprian-Matthews, the vice president for news for CBS News. Executives at the major networks said in interviews that they don't expect to be able to project a winner at 11 p.m. this year, given the closeness of the presidential race in several swing states. "I'm not even going to guess what time it will be," said Marc Burstein, the senior executive producer for special events at ABC News. He predicted an abundance of caution this year because of the trend of early voting in many states. For election night ABC is uniquely situated in Times Square, which filled up with supporters of Mr. Obama on election night in 2008. This time, too, "I expect a gigantic crowd," Mr. Burstein said. NBC is expecting the same at Rockefeller Plaza, which it has re-christened Democracy Plaza with exhibits and video screens, just as it did in 2004 and 2008. All of the executives interviewed said they would be entirely comfortable making projections after their competitors. "In a close contest, we'll simply wait," said Sam Feist, the Washington bureau chief for CNN. And all of them cited the journalism chestnut that it's better to be right than first. "It's always lovely when the two coincide," said Ms. Ciprian-Matthews of CBS, "but everybody here is absolutely on the same page: accuracy comes first." Fox News did not respond to an interview request. CNN, which was criticized for crowding its studio with anchors and analysts in 2008, will have more reporters in the field this time, including a half-dozen in Ohio alone. Reprising what it called "ballot cams" on primary nights, CNN will have crews at "key voting and vote-counting locations" in battleground states, Mr. Feist said. "We proved during the primaries that doing real reporting on those nights can make a difference," he said. No matter the outcome, some partisans will claim that the election is illegitimate, if the election year rhetoric is to be believed. Continuing an effort that started in 2004, networks and other news outlets will ask the public to alert them to voter irregularities and allegations of voter suppression. "We have an entire team working on those stories," Mr. Lukasiewicz of NBC said. Dozens of news and opinion Web sites will offer essentially live coverage on election night, some with TV-like newscasts and others with live blogs. But the biggest audiences are still expected to tune to the big three broadcast networks, ABC, CBS and NBC, and the big three cable news networks, Fox News, MSNBC and CNN. Four years ago, Brian Williams was the anchor on NBC, Charles Gibson on ABC and Katie Couric on CBS. Mr. Williams is back for his second presidential election night as anchor, but Mr. Gibson, who retired three years ago, will not; heading the coverage instead will be the pair that sat alongside him in 2008, Diane Sawyer and George Stephanopoulos. Ms. Couric, now of ABC, will join them from time to time with social media reaction - a role that did not exist on the network's coverage last time. On CBS, Scott Pelley will anchor his first presidential election night. It's also the first time for Rachel Maddow, on MSNBC, and Bret Baier and Megyn Kelly, on Fox News. On PBS, Gwen Ifill and Judy Woodruff will make up national television's first two-woman anchor team on election night. Half a dozen smaller channels will also have hours of live election talk, as will countless local stations - paid for in part by the revenue from innumerable election ads. Discussing the extent of the coverage, Mr. Feist of CNN said, "You cannot find an available high-definition satellite path for Tuesday night in this country. There are none left. The country is at capacity.