Teaching data structures with beSocratic

This paper describes a novel intelligent tutoring system called beSocratic, which targets question types that allow students to respond with free-form input but are able to be automatically evaluated and analyzed. Using beSocratic's GraphPad module, students are able to draw data structures using a mouse, touch, or a stylus. Once a student has completed a question, their final answer and a replay of their actions is uploaded to beSocratic's database. This allows teachers to replay student answers and identify common mistakes. In addition, beSocratic contains a set of post-analysis tools that utilize hidden Markov modeling to cluster student submissions with similar sequences of actions. Along with the modeling, beSocratic generates several visualizations to help teachers interpret the results. This can potentially help teachers identify students who are using the same strategies to answer questions. We have begun pilot-testing its use in computer science classrooms to teach student to properly construct splay trees. The splay tree activity teaches students to construct data structures using free-form drawing and the rotations needed for the splay operation. The activity concludes with an extended example where students must construct a splay tree from scratch. At each step, GraphPad evaluates how the students are performing and provides feedback. Students responded positively to the initial pilot study and we believe this warrants further investigation. beSocratic is free to use at beSocratic.clemson.edu.

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