( Para ) , POS , syntactic dependency tree ( DT ) , syntactic constituent tree ( CT ) , named entities ( NE ) , WordNet Relations ( WNR ) , WordNet supersenses ( WNSS ) , semantic role labeling ( SRL ) , causal relations ( CR ) , query classes ( QC ) , query-log co-ocurrences ( QLCoOcc ) .Models : bag-of-words scoring ( BOW ) , tree matching ( TreeMatch ) , linear ( LM ) , log-linear ( LLM ) , statistical learning