How can a single person understand whatampampamprsquos going on in a collection of millions of documents This is an increasingly widespread problem sifting through an organizationampampamprsquos emails understanding a decade worth of newspapers or characterizing a scientific fieldampampamprsquos research. This monograph explores the ways that humans and computers make sense of document collections through tools called topic models. Topic models are a statistical framework that help users understand large document collections not just to find individual documents but to understand the general themes present in the collection.Applications of Topic Models describes the recent academic and industrial applications of topic models.