Perplexity is a common metric to use when evaluating language models. For example, scikit-learn’s implementation of Latent Dirichlet Allocation (a topic-modeling algorithm) includes perplexity as a built-in metric. In this post, I will define perplexity and then discuss entropy, the relation between the two, and how it arises naturally in natural language … [Read more...] about The Relationship Between Perplexity And Entropy In NLP