It’s Not a Bug, It’s a Feature: How Misclassification Impacts Bug Prediction
|Title||It’s Not a Bug, It’s a Feature: How Misclassification Impacts Bug Prediction|
|Publication Type||Conference Proceedings|
|Year of Publication||2013|
|Authors||Herzig, Kim, Just Sascha, and Zeller Andreas|
|Secondary Title||35th Int'l Conference on Software Engineering (ICSE 2013)|
|Keywords||bias, bug reports, data quality, mining software repositories, noise|
In a manual examination of more than 7,000 issue reports from the bug databases of five open-source projects, we found 33.8% of all bug reports to be misclassified—that is, rather than referring to a code fix, they resulted in a new feature, an update to documentation, or an internal refactoring. This misclassification introduces bias in bug prediction models, confusing bugs and features: On average, 39% of files marked as defective actually never had a bug. We discuss the impact of this misclassification on earlier studies and recommend manual data validation for future studies.