sentence1: semantic similarity is a central concept that extends across numerous fields such as artificial intelligence , natural language processing , cognitive science and psychology .
sentence2: semantic similarity is a core technique for many topics in natural language processing such as textual entailment ( cite-p-22-1-7 ) , semantic role labeling ( cite-p-22-1-19 ) , and question answering ( cite-p-22-3-26 ) .