The phenomena of stupidity in online discussion forums

There is so much, it's clear, in every topic. You don't have to know much about some topics to spot obvious wrong statements. How does an online community systematically seek out and remove them to avoid them tainting discussion? Are there any ways to enter the group of smart people or is it too exclusive, or is it rather that each individual is smart at some topics but yet they talk about others into which they have projected their intelligence, i.e. a form of feeling false confidence in one's knowledge of a topic. In other words, the Dunning-Kruger effect

We are effectively trying to measure the signal-to-noise ratio of text in terms of its explanatory power of reality. How does one do that programmatically? Can it be done through a syntactical analysis of the text of all of humanity or does it require an ability to perform experiments in the real world?

I guess this is empiricism vs rationalism