NTCIR-3 WEB Experiments at Osaka Kyoiku University — Towards Index Partitioning and Parallel Retrieval —

Long gram-based indices are experimented at NTCIR-3 WEB task . To make gram-based indices, no analyses such as morphological ones are required. 2 byte characters extracted from NTCIR-3 `cooked' version of WEB task corpus. The total index size is 26 Gbyte and time to make indices is about 18 hours. Median search time per word from index is 197msec. Ranking algorithm used is based on a traditional probabilistic model. We report index partitioning which we experimented. And we propose parallel retrieval