Ben Carterette Virgiliu Pavlu Evangelos Kanoulas Javed A. Aslam James Allan Evaluation over thousands of queries. 651-658 2008 SIGIR http://doi.acm.org/10.1145/1390334.1390445 conf/sigir/2008 db/conf/sigir/sigir2008.html#CarterettePKAA08