I think it's a careful combination of things: 1) Simple UI and only one "channel". This forces all the users to take part in all the submissions resulting in a

I think it's a careful combination of things: 1) Simple UI and only one "channel". This forces all the users to take part in all the submissions resulting in a diverse set of comments and expertise on any given submission plus many eyes on fact checking. 2) As a result, the high volume of views on each submission, and the simple karma and voting system, quickly highlights the most enlightening comments and directs the conversation. 3) Votes are democratic across all users, this makes the results of voting less "tribal" and more appealing to the entire audience. 4) Branding. HN has the branding as a place for intelligent discussion with high expectations for professional quality responses and specific links to sources, and a minimum of commentary that doesn't move the conversation forward. The community holds these values very dear and they seem to me at least to be maintained pretty well. In closing though, I think it's the branding and ethos part that really does it. Nothing about the sites simple design forces this ethos I think. And as soon as people stop enforcing the ethos, or in the other extreme, become complete d*'s in doing so, nothing about the technical design of the site will keep it here. follow-up: When I bookmark anything that I find on HN, I don't ever just bookmark the link itself, I'll bookmark the HN page with all the comments as they are an incredible resource of context and introduction to the topic at hand.