We note that the Topic Coherence (TC) metric in (Mimno et al., 2011) which is often used to approximate coherence in unigram topic models as it correlates with human notions of coherence, uses codocument frequency of individual words in topics.
dataset Statistics: For CRF training, we created a phrase labeled dataset of aspect opinion phrases using product reviews from Amazon across 4 domains each spanning 4 head aspects.