I will add that when link posts have text, it's basically two separate articles that share a vote count. E.g. the front page has your link to http://greyenlightenment.com/i-can-tolerate-anything-except-factual-inaccuracies/ which people can vote on. But if they click through to the comments section, they find a secret article written by yourself, https://www.lesserwrong.com/posts/JTHbQgw94dLP34xGn/i-can-tolerate-anything-except-factual-inaccuracies, which they can also vote on. But since they're the same thing, the signal is very confused.
It's not even clear that your article is attached to a link post (e.g. someone could go there through recent comments and have no idea).
So, under the current implementation, +1 to making regular posts that contain links instead of linkposts, *especially* linkposts that also contain a regular article.
If nothing else, I would say "If the author wouldn't have been allowed to copy it into a less wrong post and put it on the front page, it shouldn't be linked from the front page". I also strongly dislike the current implementation of link posts, and would prefer that one has to click through into the comments; as such, I'd rather you just make a normal post, and make it short with a link. Perhaps describing what you're getting out of it.
I'd say I'd like to keep the ratio of linkposts low, maybe 1 in 5 at most. So frequency would be determined by ratio of non-linkposts.
In terms of age, I think it doesn't matter so much as making sure that there are no reposts whatsoever.
We do check for whether the link of a post is the same as he one of a previous post, but if the link is even slightly different that doesn't work.
one could use plagiarism detection techniques on the content of urls to suggest discussions that might be about the same content. it's kind of overkill but sounds fun to build
I'm not sure. I agree that it's not obvious how to prevent it. I think I value it despite not knowing exactly how to implement it. Ideally, "this has already been posted" would be part of the link post creation process. That only works when it's the same url, though.
There are a lot of interesting content I read on the internet (some of which may not have been produced by the rationalist diaspora (and which the authors wouldn't want to crosspost to Lesswrong)) that I nonetheless found interesting and feel like sharing with other Lesswrongers. However, I am not sure if the posts would be well received. I have not found explicit discussion (I searched the titles in Meta) indicating what is and is not acceptable to be linked. I don't want to gain information by experimenting (which has significant negative externalities for both me and the community. Me in the form of lost karma, and the community in the form of degradation of quality, and annoyance/displeasure of community members). I would appreciate if the norms for link posts were explicitly outlined, so that I would know if a link is acceptable or not.
Points that I feel should be explicitly spelled out:
Time: Are links older than <insert time frame here> not allowed?
Frequency: Should we limit our link posts to a certain frequency? One a week, One a day? Not more than X a day?
Content: What topics are not acceptable for link posts (if it is the same as for front page posts, then feel free to skip this). If link posts have a wider or narrower scope please indicate this.
I think those are the main areas for which I would appreciate explicit guidelines as far as link posts are concerned.