Why are Bug Reports Invalid?

Invalid bug reports cause overheads in the software process. This study examined the invalid bugs reported against a server application over four years time period and categorized the reasons. The research found that in addition to errors in testing, misunderstandings on functionality and environments, lack of background knowledge, problems in external systems and tools, and other reasons can lead to invalid bug reports. The details in each category were explored to reveal the weaknesses and mistakes in reporting invalid bugs. Based on these findings, the research proposed some suggestions on improving bug reporting quality and avoiding invalid bugs, such as optimal documentation and communication, sufficient training and learning, proper role setting, and testing methods like pair testing, etc. The value of this research is to share the experiences in software QA activities and provide references for other projects.