Inverting the question might be more useful:<p>- What are the characteristics of interesting discussion?<p>- What are the requirements necessary to meet those characteristics?<p>The DL;DR: is that conversation is hard, and it scales poorly. Twitter meets the fundamental requirements poorly. As to most technological platforms.<p>The underlying question and problem is the one that philosophers have tried to address for millennia, in particular the distinction between the philosophers and the sophists (dialectics and rhetoric). Twitter is principally a rhetorical channel.<p>I think it's Juergen Habermas who has done some work on participative democracy / group truth-seeking, though I've been at a loss for the specific reference or terminology, or even if he's the key figure in the movement. That said, there are domains, particularly truth-and-reconciliation movements, which also apply similar principles.<p>If you're looking for informed expertise, some level of reputation, garbage collection, and gatekeeping is required. Soft methods work better than hard ones (see HN's own moderation policies and practices for an excellent example). Ungated forums tend toward noise.<p>The flipside is that <i>gated</i> forums tend toward groupthink and self-selection mechnisms, typically favouring conformity over correctness or truth value.<p>And there are other goals of various communities. There's story-telling, community-building, support and encouragement, entertainment, teaching, demonstrating capabilities (and its flipside: "virtue signalling" or "alliegience signalling").<p>My best results have been with smaller groups of reasonably-well selected people. Anything much over 50 people seems to fall apart fairly quickly. HN itself isn't perfect, but among larger forums is among the best I'm aware of, and has been for over a decade, whcih is a remarkable record.<p>Communications turns out to be complicated. Especially between people.