For the last year or so, one of my research activities has been exploring the design and delivery of coderetreats. Our first article on this topic Coderetreats: Reflective Practice and the Game of Life was published in IEEE Software, the first piece of academic work to be published in this area. In that article we reported on how running a standard coderetreat with our students helped develop their reflective practice. In a post late last year I mentioned the Global Day of Coderetreat. We also gathered data from that event, which raised some interesting questions about how well these activities support the use of test driven development (TDD) and learning about the four principles of simple design. The coderetreat website (coderetreat.org) says that ‘Practicing the basic principles of modular and object-oriented design, developers can improve their ability to write code that minimizes the cost of change over time.’ These principles are outlined elsewhere as the ‘XP Simplity Rules‘. However there was some evidence from our research that the usual approaches to coderetreats were not particularly effective at making these design rules explicitly understood. We also observed that many participants struggled to get started with their first unit test.
To try to address these issues, we re-engineered our most recent coderetreat so that it scaffolded the intended learning outcomes explicitly. For the first session we provided the first unit test, and suggested the second. This had a remarkable effect on how quickly the participants got into the TDD cycle. We also designed each session so that it directly addressed one of the four principles of simple design, by providing various code and test components, building on the concept of the legacy coderetreats that have been run by others. In fact the last session was very much in the legacy coderetreat style, where we provided some poorly written ‘legacy code’ without tests, which the participants had to refactor by first adding unit tests.
We have yet to analyse the data we gathered in detail, but we do believe that there is a lot of scope to take the coderetreat idea forward with new ways of ensuring that the key elements of design understanding are made explicit in the outcomes.