Another drawback of VerbNet is its organization into Levin's classes (Levin, 1993), namely, 329 groups of verbs sharing the same syntactic behavior, independently of their meaning.
while PropBank roles do not provide clear explicit semantics, FrameNet roles are explicit but frame-specific (e.g., Ingestor and Ingestibles for the "Ingestion" frame, or Impactor and Impactee for the "Impact" frame).