Predictor.com uses data from 15 online courses with 500,000 students to build a predictive model using quadratic discriminant analysis that can determine if a student will complete a course with an F1 score of 86%, precision of 84%, and recall of 88%. The model found that factors like time spent, number of days worked, time lag between activities, gender, education level, country, and age were the most relevant predictors of student success. The site then uses this model to provide course recommendations personalized for each user based on their characteristics and the transition patterns of previous students.