关键词: 位置语言模型, 平滑, 互信息, 信息检索, 语义关系

Abstract: Because positional language models did not consider semantic relationship between the words in different positions, the authors present an effective model named “positional language models with semantic information”. Firstly, the authors use Gaussian kernel function to measure the position relationship between words. Secondly, the authors present a technology which is named “smoothed mutual information” to measure semantic relationship between the words, and also prove that smoothed mutual information can effectively solve the problem that a large number of two words could not calculate the transition probability between them only by mutual information. Then the authors prove that positional language models are a special case of positional language models with semantic information. Finally, applying this new model to the area of information retrieval can obtain a retrieval model based on the new model. The experiment show that the retrieval model based on the new model performs better than a retrieval model based on positional language models for using in information retrieval.

Key words: positional language models, smooth, mutual information, information retrieval, semantic relation