DescriptionYelp is a website and mobile app which publishes crowd-sourced reviews about local businesses. In this thesis, we analyze data about restaurants from Yelp, specifically the reviews, to predict the star-ratings of the restaurants based on the contents of the reviews. Our results are based on performing sentiment analysis on the reviews, which involves determining whether a review is positive or negative. Various machine learning techniques were applied to the data after appropriate extraction of linguistic features, to create classification models, and to predict star---ratings based on these models.