If it ain’t broke, don’t fix it. But if someone’s fixing it, then it’s difficult to believe it ain’t broke, right? Especially when that someone is a multibillionaire and the something is his Golden Goose:

Facebook said it had changed some of the procedures for its “Trending Topics” section after a news report alleging it suppressed conservative news prompted a Congressional demand for more transparency.

The company said an internal probe showed no evidence of political bias in the selection of news stories for Trending Topics, a feature that is separate from the main “news feed” where most Facebook users get their news.

But the world’s largest social network said in a blog post on Monday that it was introducing several changes, including elimination of a top-ten list of approved websites, more training and clearer guidelines to help human editors avoid ideological or political bias, and more robust review procedures.

As NBC’s report notes, Facebook insisted that not only did they not knowingly discriminate against conservatives, but that the output of its Trending Topics feed showed no bias at all:

Facebook said its investigation showed that conservative and liberal topics were approved as trending topics at nearly identical rates. It said it was unable to substantiate any allegations of politically motivated suppression of particular subjects or sources.

As Larry pointed out last week, selection bias is just one form of editorial tilt. Having “conservative topics” hit the feed with framing headlines designed to make them look extreme or ridiculous amounts to another form of marginalization, one with which conservatives are all too familiar. Editorial bias is not as simple as tallying up topics with hash marks and “L” and “C” columns. Even Facebook appeared to understand that at the time, as its top attorney offered up this caveat while issuing this unilateral vindication:

“Our investigation could not fully exclude the possibility of isolated improper actions or unintentional bias in the implementation of our guidelines or policies,” Colin Stretch, Facebook’s General Counsel, wrote in a company blog post.

That was then, and this is now. Even while insisting that the bias didn’t officially exist, Facebook has decided to make these significant changes in its process:

In addition, Facebook also said it would make improvements to the product and tools, including:

* We will no longer rely on lists of external websites and news outlets to identify, validate or assess the importance of particular topics. This means we will eliminate the “Media 1K” list, the list of RSS feeds used to supplement the algorithm that generates potential trending topics, and the top-10 list of news outlets.
* We are also removing the ability to assign an “importance level” to a topic through assessment of the topic’s prominence on the top-10 list of news outlets.
* We will expand our Help Center content on Trending Topics to provide more information about this feature and how it works.

Note the third change well. Until Gizmodo’s report, Facebook claimed that its Trending Topics function was completely driven by algorithms, and not by human intervention. That claim would have kept it dishonestly shielded from charges of bias had former employees not blown the whistle on the management of this feature. That lack of candor about how Trending Topics operates certainly colors claims now that their internal investigation turned up nothing wrong.

Yesterday’s announcement seems like a tacit admission that something went wrong, or at least the possibility that they couldn’t tell when their process went south. As the ACU’s Matt Schlapp told CBS last night, it’s difficult to know exactly which this means. Thanks to the fact that Facebook kept its probe in-house, it’s also difficult to know just how much deliberate bias exists within the Trending Topics feature, and how much of that might have been by design. What we do know is this — Facebook feels compelled to change its process, and why would they do so if Facebook wasn’t doing anything wrong in the first place?

One final point: this only happened because people within the organization blew the whistle, and because conservatives engage with Facebook. If either of those conditions didn’t exist, Facebook would have shrugged off this story and never bothered to deny its bias. Zuckerberg deserves some credit for sitting down and meeting with conservatives to discuss the issue, but he did that in large part because (a) Facebook had not dealt honestly with its consumers, and (b) conservatives had the economic power to wreak some havoc with Facebook and its stockholders. After this, conservatives should not celebrate a victory — it’s not yet clear that they’ve won one — but instead increase vigilance over editorial bias on the platform by strengthening our position on it. This episode shows that conservatives have leverage, and we should not discard it.