Lessons Learned from an XP Experiment with Students: Test-First Needs More Teachings

摘要

For most XP techniques only a few experimental results on their effects are available. In October 2004 we started a medium-term experiment to investigate the impact of test-first compared to a classical-testing approach. We carefully designed a controlled experiment and conducted it with 18 graduated students randomly assigned to 9 pairs. Hypotheses dealt with development speed, number of test-cases and the test-coverage when applying the testing approaches. Results show differences however not significant ones. This paper also addresses other observations we made during the experimental run. Two major problems strongly affect the results of the experiment: the low number of data points and the non-trivial question, whether students really applied test-first all the time. Although we cannot provide any new results on testing to the research community, this paper contains valuable information about further experimental studies on this topic.