Associative Search on Shogi Game Records

Associative search is information retrieval based on the similarity between two different items of text information. This paper reports experiments on associative search on a large number of short documents containing a small set of words. We also show the extension of the set of words with a semantic relation, and investigate its effect. As an instance, experiments were performed on 49,767 professional (non-handicapped) Shogi game records with 1,923 next move problems for evaluation. The extension of the set of words by pairing under semantic relations, called semantic coupling, is examined to see the effect of enlarging the word space from unigrams to bigrams. Although the search results are not as precise as next move search, we observe improvement by filtering the unigram search result with the bigram search, especially in the early phase of Shogi games. This also fits our general feeling that the bigram search detects castle patterns well.