Chinese word segmentation and its effect on information retrieval

A set of IR experiments was carried out to study the impact of Chinese word segmentation and its effect on information retrieval (IR) at the Division of Information Studies, Nanyang Technological University, Singapore. A total of four automatic character-based segmentation approaches and a manual word segmentation approach was first carried out to obtain the word segments for indexing and to evaluate the segmentation accuracy of these automatic approaches. The IR experiments study both the influence of different document segmentation approaches on IR effectiveness and the methods used for query segmentation. Traditional data recall and precision measures were used to gauge IR effectiveness. A number of queries were selected and subjected to further detailed analysis to further explore the influence of word segmentation on IR. The findings reveal that the segmentation approach has an effect on IR effectiveness. Better IR results are obtained by using the same method for query and document processing as this increase the probability of the query-document match. The recognition of a higher number of 2-character words generally contributes to the improvement of IR effectiveness. However, manual segmentation does not always work better than character-based segmentation as a result of the existence of longer words with more than two characters. No evidence is found that ambiguous words resulting from the segmentation process significantly affect IR. (C) 2002 Elsevier Ltd. All rights reserved.