How Stuff Works: A Comprehensive Topic Modelling Guide with NMF, LSA, PLSA, LDA & lda2vec (Part-1)

This article is a comprehensive overview of Topic Modeling and its associated techniques. This is the first part of the article and will cover NMF, LSA and PLSA only. The LDA and lda2vec will be covered in the next part here. In natural language understanding (NLU) tasks, there is a hierarchy of lenses through which we can extract meaning -- from words to sentences to paragraphs to documents. At the document level, one of the most useful ways to understand text is by analyzing its topics.