Searching for Illustrative Sentences for Multiword Expressions in a Research Paper Database

We propose a method to search for illustrative sentences for English multiword expressions (MWEs) from a research paper database. We focus on syntactically flexible expressions such as “regard – as.” Traditionally, illustrative sentences that contain such expressions have been searched for by limiting the maximum number of words between the component words of the MWE. However, this method could not collect enough illustrative sentences in which clauses are inserted between component words of MWEs. We therefore devised a measure that calculates the distance between component words of an MWE in a parse tree, and use it for flexible expression search. We conducted experiments, and obtained a precision of 0.832 and a recall of 0.911.