What actually happened in the pivotal January 5 Democratic debate in Manchester N.H.? If you weren't watching yourself, the media couldn't help you much. Although journalists agreed that the debate became a battleground, there was dramatic disagreement about who was on offense and who was on defense. In fact, the country's two leading newspapers seemed to be reporting on two different debates the next morning.

According to the New York Times, Barack Obama and John Edwards combined forces to launch a joint attack on Hillary Clinton. The Times' front-page headline read, "At Debate, Two Rivals Go After Defiant Clinton." The Times story led with the news that,

"Sen. Barack Obama and John Edwards went after Sen. Hillary Rodham Clinton as never before…they entered into an alliance of convenience…. When it became clear that Mr. Obama and Mr. Edwards… were teaming up, Mrs. Clinton sat up straight and pulled her coat tight as if preparing for battle….

A charged series of exchanges first unfolded between Mrs. Clinton… and Mr. Obama… As Mrs. Clinton attacked Mr. Obama… she sought to make an ally out of Mr. Edwards.

[But] Mr. Edwards…delivered a coup de grace – siding dramatically with Mr. Obama instead of Mrs. Clinton."

So was the debate all about Edwards and Obama ganging up on Hillary? Not according to the Washington Post, whose own front page report described a feisty Hillary taking the offensive against her chief rival -- "Underdog Clinton Goes After Obama."

The Post article led with the news that "Sen. Hillary Rodham Clinton tried repeatedly to knock Sen. Barack Obama off his footing during a high-stakes debate here last night…. In comparison with some past debates, Saturday's session produced a role reversal, with Clinton playing the scrappy underdog."

The television newscasts weren't much help in sorting out these two scenarios. NBC took the Post's side in its January 6 "Nightly News" broadcast: "If there was one theme of today, it's that Barack Obama is the front-runner here and also because of that he's a target. We saw it during the debate last night…. Hillary Clinton took on the risky task of going on the offensive, continuing her attacks on Barack Obama's message of change that she started during Saturday night's Democratic debate.

On the other hand, ABC's "World News Sunday" seemed to accept the Times' version: "in last night's debates … Romney's Republican rivals teamed up against him and Clinton's Democratic rivals pounced on her…. Today, Edwards told George Stephanopoulos he didn't discus confronting Clinton with Obama beforehand, but said they do have an alliance."

Other leading national news outlets like CBS and USA Today couldn't clear up the confusion because of the debate's Saturday night timing. The Sunday "CBS Evening News" was preempted by football, and neither USA Today nor the Wall Street Journal publishes on Sundays.

To some degree this is all a matter of editorial judgment or a question of emphasis. But these stories also relate two different versions of reality – on one hand, two challengers got together to gang up on a mutual rival. On the other, the top dog turned underdog lashed back against her leading challengers. The difference between these two narratives is also partly a matter of fact -- who attacked whom and how often?

To find out who was right, we analyzed the actual exchanges among the candidates throughout the entire debate, taking note of the source and target of every attack. Our examination was based on a content analysis system developed by the Center for Media and Public Affairs.

The results: Barack Obama and John Edwards each directly attacked Hillary Clinton only twice. Obama launched the same number of attacks launched against Edwards, who never attacked Obama. By contrast, Sen. Clinton attacked Obama eight times and Edwards once. So she played offense more often than defense, while her two leading opponents returned fire only occasionally.

Examples:

Clinton on Obama: "you said you would vote against the Patriot Act. You came to the Senate; you voted for it;" "you stopped short of going the distance to make sure that we had a system that could actually deliver health care for everyone;"

Obama on Clinton: "your premise is, they [the public] won't buy it [health care] even if it's affordable I disagree with that."

Edwards on Clinton: "Every time I fight for change, the forces of the status quo are going to attack… I didn't hear these sorts of attacks from Sen. Clinton when she was ahead."

So what was going on during the rest of the 45 minute debate? First, the participants spent time going positive – citing their own achievements and arguing for the merits of their policies. Several times, in fact, they lauded the positions of their opponents onstage. Second, they directed their anger against the Bush administration, which they criticized far more often than they did each other.

Finally, what does it matter who charged whom with what? For one thing, American voters like positive campaigners (even if they are influenced by negative information). Nobody wants to be seen as angry or downbeat, which is why candidates frequently delegate attacks to their surrogates or television ads. For another, research shows that voters learn little about substantive issues from television news, but they learn a great deal about the horse race. Indications that a candidate is on the defensive or losing ground can become self-fulfilling prophecies at the polls. Finally, suggestions that the candidates are highly negative increases voter cynicism and reduces turnout – something the media should consider when they play up the conflicts on the campaign trail between now and November.