Over at Slate, Jeremy Singer-Vine has just published the results of a three-week study on how often Politico modifies major stories without notifying readers that the article has been updated, or, more often, without explicitly spelling out what was corrected or changed.

Singer-Vine wrote a simple computer script that regularly trawled and tracked Politico copy, watching for modifications. Very clever.

Slate’s research, which focused on a set of 400 articles linked from the site’s front page, found that only about three percent of articles underwent “significant” post-publication revision. He provided Politico a copy of his findings before publication, after which the site added correction notices to a half dozen10 of the spotlighted articles.

That list is published as a very handy sidebar, complete with the relevant original and modified text.

The study, Singer-Vine told me, was inspired by a Kicker post of mine from last month noting the deletion of a section of a Politico story suggesting that Michael Hastings, the Rolling Stone freelancer who wrote the profile that led to the departure of General McChrystal, would be more likely to write a career-killing article than a beat reporter dependent on access. The sentence was noted by many as an oddly revealing admission. Politico declined to comment on the excision when contacted by CJR, but after my post the deletion became the subject of some controversy. A Politico editor then chimed in to say that the paragraphs were removed simply to tighten and improve the article’s flow after many rewrites.

Only one of Singer-Vine’s revisions—in regards to the crime-reporting track record of Al Gore’s sexual assault accuser—is a revision that removed an editorial assertion. The rest are plain factual errors which, in the old days, would routinely draw a printed correction.

Here’s Singer-Vine’s conclusion:

Politico seems to have rewritten the old wire-service motto. It’s no longer, “Get it first, but first get it right.” For Politico, it’s more like, “Get it first, and if you don’t get it quite right, quietly change it later.”

Update, 11:45 AM: Ha. Slate updated its story late last night to note that “many of the changes Politico made to its stories would have been permitted under Slate’s own corrections policy. Under Slate’s policy, we do not notify readers about minor corrections that we ourselves catch within 24 hours of publication.” That daylong window of time would include all but one of Slate’s spotted errors. Among several other mistakes in Singer-Vine’s piece (now cataloged on Slate’s site) Slate indicated that Politico had only appended corrections to six of the 12 highlighted articles after Slate provided Politico with its findings. In fact, Politico appended corrections to ten of the articles yesterday afternoon. I hope to have more on this soon.

Clint Hendler is the managing editor of Mother Jones, and a former deputy editor of CJR.