We examine whether augmenting traditional coding environments with prodirect manipulation improves several learning measures. Prodirect manipulation is a novel user interaction model that provides a bidirectional link between code and outputs. Instead of reasoning abstractly about outputs a program could produce, users instead directly manipulate the outputs of a computation (e.g., using a keyboard and mouse). Program text is then updated to reflect the change. We report the effects on learning using a prodirect manipulation environment versus a standard development environment for more than one hundred middle school students.

To conduct the study, we built SWELL, a programming language and integrated development environment that includes a prodirect manipulation interface. Based on our study, we conclude that within the context of an Hour-of-Code course, prodirect manipulation interfaces do not offer a significant advantage. At the same time, we make several observations regarding the way students interact with SWELL, which could inform future programming language design for this age group.