Characterizing the transfer of program comprehension in onboarding: an information-push perspective

Many software developers struggle to understand code written by others, leading to increased maintenance costs. Research on program comprehension to date has primarily focused on individual developers attempting to understand code. However, software developers also work together to share and transfer understanding of their codebases. This is common during the onboarding process, when a new developer has joined a project or a company. The work reported here uses a Grounded Theory approach to explore the different types of information passed from experts to newcomers during onboarding, and the perceived value of these types. The theory is grounded in field-study data collected during twelve in-situ onboarding sessions, across eight organizations, with a design based on two pilot studies that were carried out in advance. The field-study data was supplemented and validated with interviews and questionnaires. It provides a description of four views through which the experts represent their code to the newcomers, revealing several interesting aspects of expert-led program comprehension. In particular, it provides evidence that extends current thinking on the temporal aspect of code: where experts discuss changes that have been made to the code-base, changes that are currently being made to the code-base (including temporary fixes) and changes intended for the code-base in the future. In addition, a rationale-based view of the code-base is emphasized in the findings, making explicit the system’s functional/non-functional requirements, and their impact on the system’s design. This information was perceived as highly valued by the newcomers. Additionally, Structural and Algorithmic views, which have already been firmly established in program comprehension literature, were also noted in these onboarding sessions.