A Survey on Automatically-Constructed WordNets and their Evaluation: Lexical and Word Embedding-based Approaches

WordNets - lexical databases in which groups of synonyms are arranged according to the semantic relationships between them - are crucial resources in semantically-focused natural language processing tasks, but are extremely costly and labour intensive to produce. In languages besides English, this has led to growing interest in constructing and extending WordNets automatically, as an alternative to producing them from scratch. This paper describes various approaches to constructing WordNets automatically - by leveraging traditional lexical resources and newer trends such as word embeddings - and also offers a discussion of the issues affecting the evaluation of automatically constructed WordNets.