Automatic evaluable test of the algebra knowledge of first year students

Untrained students do not yet know how to enter solutions in STACK. In this article, an automated pre-processing is presented. With the help of the pre-processing, even inexperienced students can perform an automated diagnostic test of elementary algebra with high recognition rates in STACK. Why pre-processing can be an important tool in automated evaluation is demonstrated by the example of a task of “understanding the letters” according to Küchemann. For this purpose, data collected in the aldiff project of the Heidelberg University of Education is analyzed; aldiff develops an automated test of elementary algebra knowledge.