Parse Forest Computation of Expected Governors

In a headed tree, each terminal word can be uniquely labeled with a governing word and grammatical relation. This labeling is a summary of a syntactic analysis which eliminates detail, reflects aspects of semantics, and for some grammatical relations (such as subject of finite verb) is nearly uncontroversial. We define a notion of expected governor markup, which sums vectors indexed by governors and scaled by probabilistic tree weights. The quantity is computed in a parse forest representation of the set of tree analyses for a given sentence, using vector sums and scaling by inside probability and flow.

• Type: Conference
• Year: 2001
• Where: ACL
• Authors: Helmut Schmid, Mats Rooth
• Keywords: ACL 2001, ACL 2007, Grammatical Relations, Headed Tree, Probabilistic Tree Weights