A quantitative measure is required to reliably evaluate the achieved improvement. One of the methods proposed to measure the interpretability is the word intrusion test BIBREF41 . But, this method is expensive to apply since it requires evaluations from multiple human evaluators for each embedding dimension. In this study, we use a semantic category-based approach based on the method and category dataset (SEMCAT) introduced in BIBREF27 to quantify interpretability. Specifically, we apply a modified version of the approach presented in BIBREF40 in order to consider possible sub-groupings within the categories in SEMCAT.  
 Question: What experiments do they use to quantify the extent of interpretability?
Human evaluation for interpretability using the word intrusion test and automated evaluation for interpretability using a semantic category-based approach based on the method and category dataset (SEMCAT).