Norwegian public broadcasting company NRK recently unveiled a feature geared towards keeping comments on their website civil. Reader are required to answer a basic quiz to ensure they understand what the article is about before commenting.
It's definitely a unique approach, and certainly one that I think many people have suggested in jest. It'd be particularly nice to see this more widely implemented in this era of fake news.
Some other companies doing good work in this space — by my estimation — include Discourse, Disqus and Civil. Moderating comments to keep them spam-free and constructive is a challenge and why I don't have comments on this site as of writing this.
What makes NRK's approach unique though is it's not precisely solving the spam or civility problem inherent with commenting systems — it's trying to tackle the comprehension problem, which is a much deeper issue on news sites.
I'll be curious to see if other mainstream publications adopt this approach.