Comparison Systems
	• MITRE –baseline – Stemmed word overlapping – Baseline in previous work on passage retrieval evaluation • SiteQ – top performing density based method – using 3 sentence window • NUS – Similar to SiteQ, but using sentences as passages • Strict Matching of Relations – Simulate strict matching in previous work for answer selection – Counting the number of exactly matched paths • Relation matching are applied on top of MITRE and NUS