Students' Program Comprehension Processes in a Large Code Base

Program comprehension (PC) literature typically focuses on industry professionals comprehending large code bases or novice programmers comprehending short programs. As a result, limited work has aimed to understand how intermediate programmers comprehend large code bases, especially with the goal of supporting learners' incremental development of program comprehension expertise. Through the lens of the Block Model-a theory to support research on and teaching of PC-we aim to uncover 1) the comprehension process that intermediate programmers follow (i.e., top-down, bottom-up, etc.), and 2) common mappings between comprehension techniques used by intermediate programmers and comprehension blocks in the Block Model. We present a diary study of students' “process journals” inwhich they described their PC process while modifying the open-source idlelib code base. Our results showed that students typically followed a top-down and Text-first approach to understand a feature in the idlelib code base. Our findings also reveal how students used various program comprehension techniques (such as code navigation, using the IDE-based debugger, making experimental code changes, etc.) in terms of the Block Model. These findings make progress toward bridging our theoretical understanding of novices' comprehension process in small programs and expert's code comprehension process in large code bases by presenting a high sample size investigation of intermediate programmers' PC processes in a large, existing code base. Instructors can use our findings to understand which blocks in the Block Model are cover PC techniques, which can enable targeted teaching activities to impart PC skills.