What is perplexity ? Where do you typically use perplexity ?

Perplexity is a measure used in probabilistic modeling. In NLP it is used to measureĀ  how well the probabilistic model explains the observed data. It is closely related to likelihood, which is the value of the joint probability of the observed data. Suppose the model generates data , then the perplexity can be computed as:…

How to measure the performance of the language model ?

While building language model, we try to estimate the probability of the sentence or a document. Given sequences(sentences or documents) like     Language model(bigram language model) will be :     for each sequence given by above equation. Once we apply Maximum Likelihood Estimation(MLE), we should have a value for the term . Perplexity…