Brian, I am working on a similar project. - How to we get around the political polarization and gridlock to find the solutions that unite us.
I think there is no, one solution and you have to many things. Here is what we've figure out about the methods you mentioned:
- human moderators - even with good intentions they are corruptible, especially over time when large sums of money are involved. (eg Congress). But it's also very hard to be unbiased and remain so over time. But what if you have 160M participants. It doesn't scale with consistency.
- algorithmic moderation - while simple strait forward checks are appropriate the algorithms used need to be transparent and well understood by the participants. If people don't understand why their posts get rejected the system will lose legitimacy. (School teachers in some places are going crazy because their evaluations depend on algorithmic calculations based on student test scores that they have no visibility into, and the algorithms are proprietary)
- user selection filtering - important but only goes so far - you want to make sure that people are confident that other people only get one account, and that appropriate people are participating (eg. not the ones's hired on fiverr to vote up a point). But it's a democracy and everyone should get to participate.
What we're working on is more like reddit's voting up process. Each post is shown to a small random group of people. They can vote it up. If no one votes it up then it only impacted that small group, but not the entire community. Also, people are encouraged to give feedback so that the person can learn how what they wrote is perceived by other people.