Human-inspired semantic similarity between sentences

Following the Principle of Compositionality, the meaning of a complex expression is influenced, to some extent, not only by the meanings of its individual words, but also the structural way the words are assembled. Compositionality has been a central research issue for linguists and psycholinguists. However, it remains unclear how does syntax influence the meaning of a sentence. In this paper, we propose an interdisciplinary approach to better understand that relation. We present an empirical study that seeks for the different weights given by humans to different syntactic roles when computing semantic similarity. In order to test the validity of the hypotheses derived from the psychological study, we use a computational paradigm. We incorporate the results of that study to a psychologically plausible computational measure of semantic similarity. The results shown by this measure in terms of correlation with human judgments on a paraphrase recognition task confirm the different importance that humans give to different syntactic roles in the computation of semantic similarity. This results contrast with generative grammar theories but support neurolinguistic evidence.