Algebra addresses mathematics that is crucial for further study of STEM concepts and for work in many technical careers. Yet many high school students struggle to pass Algebra. Cognitive Tutor Algebra 1 (CTA1) is a curriculum that includes both textbook components and an automated computer application that is designed to deliver individualized instructions to students. This project will build on the findings of a randomized control experiment that examined the effectiveness of CTA1. The researchers will study the mechanisms by which CTA1 achieves its effect by examining patterns in logs of students' actions and progress while they use the program, teacher survey data and student achievement data. The project will employ Bayesian statistical models to infer if causal models exist that explain the relationship between positive learning outcomes and the use of the curriculum.
The PIs will use a specific form of mediation analysis, the Rubin Causal Model, to develop and test hypotheses about what the students would have experienced with CTA1 versus what they would have experienced in its absence. This analysis methodology supports the identification of mediating variables on the relationship between a treatment assignment (CTA1) and an outcome (student achievement). The study also tests the use of a particular form of mediation analysis, principal stratification, to determine its utility in conducting such analyses. Multiple mediation models will be examined to determine how educational researchers might develop better experimental research studies.
