NTCIR-5 Patent Retrieval Experiments at Hitachi
Hisao Mase, Tadataka Matsubayashi, Yuichi Ogawa, Takaaki Yayoi, Yusuke Sato, Makoto Iwayama · 2005
In NTCIR-5, we used five retrieval methods proposed in NTCIR-4: (1) query term weighting using only document frequency, (2) stopword deletion, (3) two-stage patent retrieval, (4) term weighting considering “measurement terms”, and (5) related term expansion. In this paper, we compare the retrieval accuracy for two test sets: 34 main queries