  The ranked retrieval model has rapidly become the de-facto way for search
query processing in web databases. Despite the extensive efforts on designing
better ranking mechanisms, in practice, many such databases fail to address the
diverse and sometimes contradicting preferences of users. In this paper, we
present QR2, a third-party service that uses nothing but the public search
interface of a web database and enables the on-the-fly processing of queries
with any user-specified ranking functions, no matter if the ranking function is
supported by the database or not.
