Not all duplication is bad. If you live to be long enough, you'll typically spot a cycle of stories carried in the mainstream media: local media's recycling of "places to visit" and "quaint historical anecdotes" items (new to me in my youth, somewhat less so in my dotage), the very, very predictable seasonal trend, particularly in consumer business stories around holidays, election cycles, etc.
In the case of HN, there are submissions I've seen which have gone down with no appreciable comment which, one or two or four years later, may well deserve a re-hearing. At the same time, you'll get iterations on a specific theme (a recent instance being 2^11 stories) which, while different in source, are often largely similar in content and significance. HN penalizes the former while passing on the latter. I'd prefer that reversed.
I've grown increasingly impressed with reddit's "related" link giving access to other discussions on a particular URL or topic. Actually, I've been growing increasingly impressed with reddit in general.
In the case of HN, there are submissions I've seen which have gone down with no appreciable comment which, one or two or four years later, may well deserve a re-hearing. At the same time, you'll get iterations on a specific theme (a recent instance being 2^11 stories) which, while different in source, are often largely similar in content and significance. HN penalizes the former while passing on the latter. I'd prefer that reversed.
I've grown increasingly impressed with reddit's "related" link giving access to other discussions on a particular URL or topic. Actually, I've been growing increasingly impressed with reddit in general.