Detection of Topic and its Extrinsic Evaluation Through Multi-Document Summarization

This paper presents a method for detecting words related to a topic (we call them topic words) over time in the stream of documents. Topic words are widely distributed in the stream of documents, and sometimes they frequently appear in the documents, and sometimes not. We propose a method to reinforce topic words with low frequencies by collecting documents from the corpus, and applied Latent Dirichlet Allocation (Blei et al., 2003) to these documents. For the results of LDA, we identified topic words by using Moving Average Convergence Divergence. In order to evaluate the method, we applied the results of topic detection to extractive multi-document summarization. The results showed that the method was effective for sentence selection in summarization.