Researchers from the World Association of Newspapers and News Publishers (WAN-IFRA) spoke with online editors and community managers at 104 news organizations from 63 countries to help assemble a report written by Emma Goodman about what works and what doesn't when it comes to online comments.

Many said stories about politics attracted the most high-quality comments. Several respondents, however, said such stories are "the type of articles that attract the worst comments."

Next best were niche lifestyle areas such as travel, women-specific content, cars, technology, science and history, with 12 mentions.

Sebastian Horn from Germany's Die Zeit cited "anything that is technical in nature" as a good-comment magnet. But a respondent from The Dallas Morning News told the organization most people in its newsroom "are not interested in comments or feel they’re a necessary evil."

On average, respondents said they deleted 11 percent of comments. But few organizations view moderation as a chance to do more with the remaining comments.

“Your most frequent commenters are your best customers," The Seattle Times' Bob Payne told researchers.

They know more about your site than anybody else. They know more about your reporters and how they write. And they’re constantly on your website giving you page views. And yet we do very little to acknowledge or commend these people. I think very few sites do - some give badges for most positive commenters but most don’t do anything and a lot of people wish commenters would go away. But in fact these are the people who live and breathe your site. They call it this ‘my college football blog’, 'my photo area’, not The Seattle Times because they are so ingrained in it.

Seventy-one percent of respondents said they block commenters who violate their rules. The Winnipeg Free Press said it uses "what we call a bozo filter" to block trolls: Such posters still see "their comments but no one else does." The New York Times' Bassey Etim says the organization has blocked people "maybe once or twice in our history."

The report recommends best practices for publishers, including hiring a community manager and encouraging journalists to join discussions. Publications should also try to "protect minority opinions," it says: "If a publication moderates actively, they can use this procedure to ensure that minority voices aren’t continuously drowned out."

Related: Popular Science editor: Comments ‘became too much to really fight back’ against | NYT community manager: Good comments shouldn’t sit among those designed to cause conflict | 25% of people have posted anonymous comments, Pew finds | Huffington Post deletes 75 percent of incoming comments

Related training: Managing Comments on Your News Site | Designing the Web for Democracy