Type Circuits: A Visual Computer Science Activity for Connection-Making and Confidence

In computer science and other STEM subjects, a major factor in students’ confidence is whether they treat errors as learning opportunities. Some of the most challenging error messages students receive are produced as the result of an information-rich connection-making process by the computer known as type inference. However, this underlying process is hidden, which can leave students frustrated, confused, or discouraged when they encounter error messages. If students were able to observe and practice the computer’s connection-making process for themselves, errors could be reframed as a pedagogical tool rather than a source of frustration. The purpose of this study is to determine whether students can build deeper understanding and confidence surrounding programming errors through a scaffolded, visual introduction to type inference. To this end, I developed Type Circuits, a web-based program visualization tool that can automatically create printable classroom activities for modeling type inference. In this study, I will evaluate the tool and activities in a high-school computer science classroom in the Northeast United States. The study will answer the following research questions: RQ1. How do novices engage with type inference visualizations? (engagement) RQ2. Do type inference visualizations improve novices’ ability to explain programs and error messages? (understanding) RQ3. Do type inference visualizations increase novices’ confidence in understanding and resolving error messages? (confidence)