The most intuitive way to represent syntactic information is to use individual dependency relations directly, like dependency head and dependency relation label, denoted as Dep and Rel for short. In order to preserve the structural information of dependency trees as much as possible, we take the syntactic path between candidate arguments and predicates in dependency trees as linguistic knowledge. Referring to BIBREF9, we use the Tree-based Position Feature (TPF) as Dependency Path (DepPath) and use the Shortest Dependency Path (SDP) as Relation Path (RelPath). 
 Question: What different approaches of encoding syntactic information authors present?
dependency head and dependency relation label, denoted as Dep and Rel for short Tree-based Position Feature (TPF) as Dependency Path (DepPath) Shortest Dependency Path (SDP) as Relation Path (RelPath)