Assessing textual source code comparison: split or unified?

Evaluating source code differences is an important task in software engineering. Unified and split are two popular textual representations supported by clients for source code management. Whether these representations differ in supporting source code commit assessment is still unknown, despite its ubiquity in software production environments. This paper performs a controlled experiment to test the causality between the textual representation of source code differences and the performance in term of commit evaluation. Our experiment shows that no significant difference was measured. We therefore conclude that both unified and split equally support the source code commit assessment for the tasks we considered.