When a bug is fixed, programmers are supposed to report where it is repaired. The association of the bug, and the repair is critical to quality-improvement efforts, such as bug prediction and defect etiology and avoidance. But what if programmers don't tell us where all the bugs are fixed?If they fail to report bug fixes, or worse, do the reporting in a slective manner, we might get a biased sample of bug-repair data, which would threaten the validity of studies using this data.

Dozens of papers have been written using open-source bug-repair data. We have studied this data for evidence of bias in reporting, and evaluated the potential effects of this bias on prediction.

Prem Devanbu received his B.Tech from IIT Madras, and his Ph.D from Rutgers University in 1994. He worked
for many years at Bell Labs in Murray Hill before switching to UC Davis in 1998, where he is now on the faculty of Computer Science. He has been on the editorial boards of IEEE Transactions on Software Engineering, the ACM Transactions on Software Engineering and Methodology, and the Empirical Software Engineering Journal. He has been program chair of ACM SIGSOFT FSE in 2006 and is program chair of ICSE 2010. His research interests include empirical software engineering and open source software.