Symbolic, Distributed and Distributional Representations for Natural Language Processing in the Era of Deep Learning: a Survey
It addresses the foundational problem of understanding how discrete symbols are represented in neural networks for the NLP community, but it is incremental as a survey.
The paper surveys the relationship between symbolic representations and distributed/distributional representations in NLP, aiming to renew this link to inspire new deep learning networks.
Natural language is inherently a discrete symbolic representation of human knowledge. Recent advances in machine learning (ML) and in natural language processing (NLP) seem to contradict the above intuition: discrete symbols are fading away, erased by vectors or tensors called distributed and distributional representations. However, there is a strict link between distributed/distributional representations and discrete symbols, being the first an approximation of the second. A clearer understanding of the strict link between distributed/distributional representations and symbols may certainly lead to radically new deep learning networks. In this paper we make a survey that aims to renew the link between symbolic representations and distributed/distributional representations. This is the right time to revitalize the area of interpreting how discrete symbols are represented inside neural networks.