Understanding How Pair Programming Actually Works in Industry: Mechanisms, Patterns, and Dynamics

Abstract

During pair programming (PP), two software developers work closely together on a technical task on one computer. Practitioners expect a number of benefits, such as faster progress, higher quality, and knowledge transfer. Much of prior research focused on directly measurable effects from laboratory settings, but could not explain the large variations observed. My research follows the Grounded Theory Methodology and is aimed at understanding how PP actually works by uncovering the underlying mechanisms to ultimately formulate practical advice for developers. The main findings from my qualitative analysis of recordings of 27 industrial PP sessions are: Task-specific knowledge about the software system is crucial for pair programming. Pairs first make sure they have a shared understanding of the relevant parts before they acquire lacking knowledge together. The transfer of general software development knowledge plays a rather small role and only occurs after the pair dealt with its need for system knowledge. Pairs who maintain a shared understanding may have short, but highly-productive Focus Phases; if their Togetherness gets too low, however, a Breakdown of the pair process may occur.