Grammatically-Interpretable Learned Representations in Deep NLP Models

We introduce two architectures, the Tensor Product Recurrent Network (TPRN)
and the Tensor Product Generation Network (TPGN). In the application of TPRN,
internal representations — learned by end-to-end optimization in a deep neural network
performing a textual QA task — are interpretable using basic concepts from
linguistic theory. This interpretability is achieved without paying a performance
penalty. In another application, image-to-text generation or image captioning,
TPGN gives better results than the state-of-the-art long short-term memory (LSTM)
based approaches. Learned internal representations in the TPGN can also be
interpreted as containing grammatical-role information.