No, but I do know some reasons why you don't see them.
Conventional search engines return a score from 0..1 which is not closely related to the probability that a document is relevant. Often a score of 1.0 gives at best an 0.7 chance of being relevant, and it rapidly gets worse from there.
Thus if you sort documents by time and then cut off at some particular score you never find a place where the recall is satisfactory and the relevance is not embarrassing. In the mainstream of IR research, this problem is thought of this way:
Now in principle you could do better if you created a model of relevant documents and a model of irrelevant documents, but you would have to train on a lot of documents, and good results could be tough because irrelevant documents could be a million times or more common than relevant documents, particularly on the WWW where even "relevant" documents are often trash documents. (ex. spam, accidental or deliberate duplicates, have pop-ups, etc.)
Anyway, I would be glad to talk more about it, click on my HN user link and send me an email.
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[ 0.22 ms ] story [ 22.1 ms ] threadConventional search engines return a score from 0..1 which is not closely related to the probability that a document is relevant. Often a score of 1.0 gives at best an 0.7 chance of being relevant, and it rapidly gets worse from there.
Thus if you sort documents by time and then cut off at some particular score you never find a place where the recall is satisfactory and the relevance is not embarrassing. In the mainstream of IR research, this problem is thought of this way:
http://www.morganclaypool.com/doi/abs/10.2200/S00235ED1V01Y2...
Now in principle you could do better if you created a model of relevant documents and a model of irrelevant documents, but you would have to train on a lot of documents, and good results could be tough because irrelevant documents could be a million times or more common than relevant documents, particularly on the WWW where even "relevant" documents are often trash documents. (ex. spam, accidental or deliberate duplicates, have pop-ups, etc.)
Anyway, I would be glad to talk more about it, click on my HN user link and send me an email.