On the understanding of programs with continuous code reviews

Code reviews are a very effective, but effortful quality assurance technique. A major problem is to read and understand source-code that was produced by someone else. With different programming styles and complex interactions, understanding the code under review is the most expensive sub-task of a code review. As with many other modern software engineering practices, code reviews may be applied as a continuous process to reduce the effort and support the concept of collective ownership. This study evaluates the effect of a continuous code review process on the understandability and collective ownership of the code base. A group of 8 subjects performed a total of 114 code reviews within 18 months in an industrial context and conducted an expert evaluation according to this research question. This study concludes that there is a clear positive effect on the understandability and collective ownership of the code base with continuous code reviews, but also limiting factors and drawbacks for complex review tasks.