Evaluating proof blocks problems as exam questions

Proof Blocks is a novel software tool which enables students to write mathematical proofs by dragging and dropping prewritten lines into the correct order, rather than writing a proof completely from scratch. We used Proof Blocks problems as exam questions for a discrete mathematics course with hundreds of students, allowing us to collect thousands of student responses to Proof Blocks problems. Using this data, we provide statistical evidence that Proof Blocks are easier than written proofs, which are typically very difficult. We also show that Proof Blocks problems provide about as much information about student knowledge as written proofs. Survey results show that students believe that the Proof Blocks user interface is easy to use, and that the questions accurately represent their ability to write proofs.