A filter dedicated to probing one’s dislikes would have to be delicate, but could also build on the powers of large collaborative databases in the spirit of “people who disliked those, learned to like this one.” In somewhat the same vein I also, occasionally, want a bit of stuff I dislike but should learn to like. For me that might be anything related to nutritional supplements, details of political legislation, or hip-hop music. Great teachers have a knack for conveying unsavory packages to the unwilling in a way that does not scare them off; great filters can too. But would anyone sign up for such a filter?