They describe a method for augmenting existing word embeddings with knowledge of semantic constraints. The idea is similar to retrofitting by Faruqui et al. (2015), but using additional constraints and a different optimisation function.

https://i.imgur.com/zedR5FV.png


Existing word vectors are further optimised to 1) have high similarity for known synonyms, 2) have low similarity for known antonyms, and 3) have high similarity to words that were highly similar in the original space. They evaluate on SimLex-999, showing state-of-the-art performance. Also, they use the method to improve a dialogue tracking system.