MIT Technology Review Online on March 21 retracted two stories written in whole or in part by Michelle Delio, citing the publication's inability to confirm a source. On April 4, InfoWorld edited four articles by Delio to remove anonymous quotes.

Wired News has published more than 700 news stories written by Delio (under the names Michelle Delio and Michelle Finley) since 2000. In April, we assigned journalism professor and Wired News columnist Adam Penenberg to review recent articles written by Delio for Wired News.

Penenberg and his staff of graduate students at New York University reviewed 160 articles, largely from 2004, but some earlier stories were also checked.

Penenberg provided Wired News with a list of 24 stories that contained sources he could not confirm (links are included at the end of this story). Penenberg's report to Wired News can be downloaded here (PDF).

Delio, in communications with Penenberg and Wired News, stands by her reporting and the existence and accuracy of her sources. Most of Delio's sources were in fact located and confirmed by Penenberg.

The unconfirmed sources affect the content of these stories to varying degrees. For example, the Florida network tax story contains only one quote from a source Penenberg could not confirm, but the quote does not materially affect the rest of the story.

However, there are four articles in which unconfirmed sources arguably play a more prominent role.

• "Spyware on My Machine? So What?" The premise of the article is that general users don't care all that much about spyware. However, Penenberg cannot confirm any of the quotes from the users in the story.

• "Searching for Life Amid Rubble" In this article about the 9/11 rescue efforts, Penenberg was unable to trace several of the people quoted, and an apocryphal survival anecdote is included (which other reporters apparently wrote about at the time as well).

• "Meet the Nigerian E-Mail Grifters" This article is based completely on sources whom Penenberg was unable to identify.

• "Nasty Malware Fouls PCs With Porn" The anecdote at the beginning of this article features a family Penenberg was unable to contact. The family's experience was used to illustrate the extent of the problem caused by the malware.

In addition, a quote in "Patron Saint of the Nerds" is attributed to the Rev. Michael Amesse. According to Penenberg's report, Amesse says he never spoke with a reporter from Wired News. We therefore have removed the quote from the story.

Wired News is not retracting any of these stories. Rather, we are appending notes to the stories, indicating what we have been unable to confirm about them and editing them, as noted, where appropriate. By keeping these stories posted and clearly marked, we hope that our readers can help identify any sources whom we cannot track down.

In addition, Wired News will now require freelance reporters to submit contact information for all named sources. Also, anonymous sources will be used only with appropriate justification.

Wired News will continue to review the remaining Delio stories in its archive and post notes and report findings as appropriate.

If you have any information about the sources in these stories, please contact us at sourceinfo[at]wired.com.