This has been a challenge in online communities for quite sometime. Some approaches I wanted to mention are what Metafilter does, which is require people pay to

This has been a challenge in online communities for quite sometime. Some approaches I wanted to mention are what Metafilter does, which is require people pay to sign up and comment, and when they sign up they have to wait 30 days to comment. This cuts down a lot of noise and reactionary Twitter type trolling. Another I think is worth mentioning is r/NeutralPolitics on reddit. They have a pretty strict moderation policy that makes for some string signal to noise but due to it's heavy handedness I feel like it does not get enough different perspectives because the least thought out or explored do not get enough attention.