High Baseline Japanese Information Retrieval for Question-Answering

For NTCIR Workshop 7 UC Berkeley participated in IR4QA (Information Retrieval for Question Answering) as well as the Patent Mining tracks. For IR4QA we only did Japanese monolingual search. Our focus was thus upon Japanese topic search against the Japanese News document collection as in past NTCIR participations. We preprocessed the text using the ChaSen morphological analyzer for term segmentation. We utilized a timetested logistic regression algorithm for document ranking coupled with blind feedback. The results were satisfactory, ranking second among IR4QA overall submissions..