Programming Versus Natural Language: On the Effect of Context on Typing in CS1

Analyzing keystroke data from students working on essay and programming tasks, we study to what extent the difference in task context influences performance in typing. Using data from two introductory programming courses offered at two separate institutions, we compare and contrast typing speed between programming and natural language tasks. We observe that students tend to be faster at typing (the same) character pairs when writing natural language text than when learning to write code. We show that students improve on typing character pairs that appear in frequently used words in programming languages, and that typing programming constructs also improves. We find that students are faster at detecting and erasing their mistakes when typing natural language text than when programming. Our results support theories regarding contextual memory, procedural memory, and practice, and have implications for course curriculum and pedagogy design.