WASHINGTON — Former White House aide I. Lewis "Scooter" Libby is the defendant but journalism seemed at times to be on trial this week as two reporters were questioned about their methods.

Libby's attorneys asked former New York Times reporter Judith Miller about her spotty memory and former Time reporter Matthew Cooper about his sloppy note-taking and inconsistent handling of confidential sources.

It's exactly what journalism groups feared when the trial began. Roy Peter Clark, senior scholar and an instructor at the Poynter Institute journalism center, predicted when the trial started that it would make both government spin doctors and reporters look bad.

The first part of that prediction came true early in the trial. On Jan. 31, journalists had their day.

"If you take that snapshot as representative of the whole industry, it can make us look pretty bad," said Jane Kirtley, a media ethics professor at the University of Minnesota.

Libby, the former chief of staff to Vice President Dick Cheney, is accused of lying to investigators about his conversations with reporters about CIA operative Valerie Plame, the wife of a prominent war critic.

Miller and Cooper originally refused to help Special Counsel Patrick Fitzgerald's investigation, but they testified after losing court battles. Miller served 85 days in jail.

Cooper co-authored a July 17, 2003, story titled "A War on Wilson?" in which he described the Bush administration's response to prominent war critic Joseph Wilson. The story said "some government officials" identified Wilson's wife as a CIA operative.

Cooper later identified his two sources as Libby and White House aide Karl Rove. He testified about a July 12, 2003, conversation in which he asked Libby whether Wilson's wife was behind a CIA-sponsored trip to investigate an alleged Iraqi uranium deal in Niger.

On Jan. 31, Cooper testified that Libby responded with the off-the-record comment, "Yeah, I've heard that too," or "Yeah, I've heard something like that, too."

When questioned, Cooper acknowledged that conversation was off the record — a term reporters normally accept as information that cannot be used in print. Yet Cooper considered it confirmation that could be used.

Cooper also defended the article's headline by noting the question mark at the end.

When Cooper described his conversation with Libby in a later story for Time, Cooper did not say his discussion was off the record. He described it as "background" material that could be used. He acknowledged in court this week that he also changed the wording of Libby's quote for that story.

Cooper also said he didn't take any notes on that exchange or include it in his memo to his editor and fellow reporters.

"I can't explain that," Cooper said. "It was late in the day. I didn't write it down, but it is my memory."

His testimony underscores the fact that reporters may not share a common understanding of what terms such as off-the-record and on background mean.

Clark says cross-examination makes any profession look bad, from emergency room doctors to high school teachers. The craft of journalism, he says, isn't always pretty but that doesn't mean its practitioners are irresponsible.

"In this case," Clark said, "the public will be watching sausage being made."

During the trial yesterday, FBI agent Deborah Bond testified that Libby acknowledged he may have discussed with Cheney whether to tell reporters that Wilson's wife worked at the CIA.

Bond's brief description of Libby's acknowledgment was about the only new information disclosed yesterday. Otherwise, Libby's perjury trial was devoted mostly to dealing with vigorous and repeated defense efforts to exclude evidence that Fitzgerald called "the guts of our case."

U.S. District Judge Reggie Walton accepted some defense arguments and rejected others during hours-long debates held outside the jury's presence.

But the government was able to show the jury small portions of video of then-White House press secretary Scott McClellan saying President Bush would fire anyone who was found to have leaked classified information. The video also showed McClellan saying he had been assured Libby did not leak classified information.

McClellan spoke in October 2003, shortly before Libby was interviewed by the FBI.