We opened our website to public comments some three years ago, and they have posed a conundrum to us for just about as long.

But over time, we've learned some valuable lessons that have allowed us to elevate the level of discussion.

We allow commenting because we want readers and the broader Minnesota community to be able to engage with us in an ongoing debate about the important stories we cover.

Communication should be about more than us delivering news and information; we want to hear back from readers. But, we need that debate to be thoughtful and civil.

We quickly learned, along with the rest of the media world, that this goal isn't easily achieved.

It's astonishing, really, what people will say to each other when they think they have the cover of anonymity. At points, the comments on our site were so nasty that sources wouldn't talk to us for certain stories for fear they would be hazed by the commenting community.

We first tried to control this by disabling the commenting feature on crime and other sensitive stories that were sure to prompt insensitive opinions. That still wasn't enough.

Our next step was to hire and train a dozen part-time moderators, an investment of about $100,000 a year, to read every comment and remove those we deemed offensive.

Comments were also put through a profanity filter before they reached the site, and moderators would read them after they were posted.

This cleaned up about 90 percent of the problems; but it wasn't completely effective when we had a big breaking story generating scores of comments by the hour.

For example, moderators were unable to keep up with the commenting on the Arizona massacre that gravely injured U.S. Rep. Gabrielle Giffords. That meant offensive comments might be up on our site for a half hour or more, prompting complaints, before we got to them.

In mid-February, after much discussion, we began premoderating all comments except for those in sports. This meant that comments were held in a queue until someone had read and approved them, before anyone else could see them.

We also asked our moderating team to set a higher bar for civility.

We initially feared these changes might hamper the interactive nature of commenting. Last year, for example, we averaged just more than 110,000 comments per month, submitted by around 13,000 unique visitors.

Most commenters post occasionally, but some post more than 100 comments a month. And in fact, some of our most active commenters have complained that this has diminished their ability to debate with other commenters on the site.

We noticed some other interesting developments, too.

First, we have seen a noticeable reduction in personal attacks and overall snarkiness, which was our primary goal.

Our moderators and online editors are also seeing a significantly higher quality of commenting, in part because commenters are generally posting their thoughts on the story they have read, rather than sparring back and forth with each other.

We've seen no significant difference in the level of traffic to our site or in the level of commenting.

However, we did notice that our occasional commenters were posting more frequently -- up almost 11 percent -- while our most active commenters were posting less frequently, perhaps because the nature of premoderation discourages them from debating with each other.

The business of democracy can be messy, and people will disagree vehemently about the important issues of our day. We know that.

We want to host those passionate discussions about our stories and the ongoing issues of the day, but we want to do so in the intelligent manner that our readers expect.

You can share feedback on this column by e-mailing commentfeedback@startribune.com or by writing us at 425 Portland Avenue, Minneapolis, MN 55488.

Nancy Barnes is editor and senior vice president of the Star Tribune.

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