Faculty Advisor

Craig Wills

Faculty Advisor

Joseph E. Beck

Faculty Advisor

Kathi Fisler


Over the last two decades, the field of educational data mining (EDM) has been focusing on predicting the correctness of the next student response to the question (e.g., [2, 6] and the 2010 KDD Cup), in other words, predicting student short-term performance. Student modeling has been widely used for making such inferences. Although performing well on the immediate next problem is an indicator of mastery, it is by far not the only criteria. For example, the Pittsburgh Science of Learning Center's theoretic framework focuses on robust learning (e.g., [7, 10]), which includes the ability to transfer knowledge to new contexts, preparation for future learning of related skills, and retention - the ability of students to remember the knowledge they learned over a long time period. Especially for a cumulative subject such as mathematics, robust learning, particularly retention, is more important than short-term indicators of mastery. The Automatic Reassessment and Relearning System (ARRS) is a platform we developed and deployed on September 1st, 2012, which is mainly used by middle-school math teachers and their students. This system can help students better retain knowledge through automatically assigning tests to students, giving students opportunity to relearn the skill when necessary and generating reports to teachers. After we deployed and tested the system for about seven months, we have collected 287,424 data points from 6,292 students. We have created several models that predict students' retention performance using a variety of features, and discovered which were important for predicting correctness on a delayed test. We found that the strongest predictor of retention was a student's initial speed of mastering the content. The most striking finding was that students who struggled to master the content (took over 8 practice attempts) showed very poor retention, only 55% correct, after just one week. Our results will help us advance our understanding of learning and potentially improve ITS.


Worcester Polytechnic Institute

Degree Name



Computer Science

Project Type


Date Accepted





Intelligent tutoring system, Robust learning, Student modeling, Knowledge retention, Educational data mining