Currently the DE API doesn't have the concept of things decaying over time (though there are some kludgy work-arounds that a couple folks are using), but we've

Currently the DE API doesn't have the concept of things decaying over time (though there are some kludgy work-arounds that a couple folks are using), but we've got a customer of some significance that specifically needs that feature, so it'll probably make its way to the API in short order. I've thought about nudging pg to see if he'd let me goof around with the actual data some, but I've been worried that it could turn into a distraction. Beyond that there are a couple interesting things: • I have some half-nuanced thoughts on the interaction between personalized news and communities, notably that I'm not sure that people want personalized news, though they often think they do. A lot of the function of news is to facilitate "informedness" which breaks down if parts of a community are reading different things. • I'm not sure that the upvote density on HN is actually high enough to drive personalization. There aren't very many upvotes in aggregate. I only upvote a few things per week, really and the frontpage is really only the sum of < 1000 votes in a community of tens of thousands of people. It's unclear to me that people upvote things enough for there to be enough overlap to do reasonable personalization.