NLP & Language · beginner · concept 116 of 311 · Updated Nov 4, 2026

🗂️Topic Density and Topical Coverage

Topic density is how concentrated a page or a corpus is on one subject. In NLP, topic models such as LDA or BERTopic give each document a distribution over topics, and a page whose weight sits in one topic is dense; coherence scores check that a topic's top words belong together. In search, practitioners call the same idea topical coverage or 'topical authority'. Google asks for depth on a topic and names a topic authority system only for news.