A measure of how prevalent a topic is across the corpus of documents. A higher weight indicates that more documents or words (technically, tokens) in the corpus are associated with a topic.
Topic Coherence
Higher coherence scores are associated with topics that, by contrast with a random set of words, are more likely to appear interpretable as a meaningful topic or theme (or in some cases, a distinctive mode or style of discourse).
Document Entropy
Low document entropy is associated with topics concentrated in relatively few specific documents (i.e., specialized topics). High entropy indicates topics that are spread more evenly and broadly across many documents (i.e., more general topics).