Why Are Algebra Word Problems Difficult? Using Tutorial Log Files and the Power Law of Learning to Select the Best Fitting Cognitive Model. - Ethan A. Croteau; Neil T. Heffernan; Kenneth R. Koedinger (Intelligent Tutoring Systems, 2004)

Web-Based Evaluations Showing Differential Learning for Tutorial Strategies Employed by the Ms. Lindquist Tutor. - Neil T. Heffernan; Ethan A. Croteau (Intelligent Tutoring Systems, 2004)

Knowledge Tracing Over Time: A Longitudinal Analysis. - Morgan P. Lee; Ethan A. Croteau; Ashish Gurung; Anthony F. Botelho; Neil T. Heffernan (EDM, 2023)