which are expensive and time-consuming to acquire (Zelle and Mooney, 1993;Zettlemoyer and Collins, 2005;Zettlemoyer and Collins, 2007).
future directions include: PubMed-scale pathway extraction; application to other domains; incorporating additional complex states to address syntax-semantics mismatch; learning vector-space representations for complex states; joint syntacticsemantic parsing; incorporating reasoning and other sources of indirect supervision.