With teammates Pankaj Ajit, Teja Talluri, and Napol Rachatasumrit, I developed an intelligent tutor to help teach intro-level students how to make a prediction using Naïve Bayes, the “hello world” of classification problems. The tutor provides instant, personalized feedback based on user errors and hint requests. The development process involved cognitive task analysis of novice and expert strategies, as well as iterative design and user testing of prototypes.