Investigating Students' Understanding of Algebraic Letters using Latent Class Analysis

To design valid assessment tools, it is necessary to understand what hurdles, common errors and misconceptions students encounter in the tested domain. Identifying typical patterns of thinking can be helpful to diagnose and communicate students’ understanding to teachers. In this report, we investigate response patterns of 2051 German Year 7 and 8 students to six multiple-choice tasks of the SMART test “Meaning of Letters” that has been designed to assess the letter-as-object misconception. Using Latent Class Analysis, six response patterns could be identified. These patterns are described and analysed, and implications for improving the current assessment discussed.