Towards Web Search by Sentence Queries: Asking the Web for Query Substitutions

In this paper; we propose a method to search the Web for sentence substitutions for a given sentence query. Our method uses only lexico-syntactic patterns dynamically generated from the input sentence query to collect sentence substitutions from the Web on demand. Experimental results show that our method works well and can be used to obtain sentence substitutions for rare sentence queries as well as for popular sentence queries. It is also shown that our method can collect various types of sentence substitutions such as paraphrases, generalized sentences, detailed sentences, and comparative sentences. Our method searches for sentence substitutions whose expressions appear most frequently on the Web. Therefore, even if users issue the sentence query by which Web search: engines return no or few search results for some reasons, our method enables users to collect more Web pages about the given sentence query or the sentences related to the query.