An Empirical Study on Inconsistent Changes to Code Clones at Release Level


Book cover We have published an extended Journal Version of this work with Elsevier/ScienceDirect.


Current research on code clones tries to address the question whether or not code clones are harmful for the quality of software. As most of these studies are based on the fine-grained analysis of inconsistent changes at the revision level, they capture much of the chaotic and experimental nature inherent to any ongoing software development process. Conclusions drawn from the inspection of highly fluctuating and short lived clones are likely to exaggerate the ill-effects of inconsistent changes. To gain a broader perspective, we perform an empirical study on the effect of inconsistent changes on software quality at the release level. Based on a case study on two open-source software systems, we observe that only 1% to 3% of inconsistent changes to clones introduces software defects, as opposed to substantially higher percentages reported by other studies. Our findings suggest that developers are able to effectively manage and control the evolution of cloned code at the release level.

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If you would like to cite the research in your own work, please use the following citation:

 author = "Bettenburg, Nicolas and Shang, Weyi and Ibrahim, Walid and Adams, Bram and Zou, Ying and Hassan, Ahmed E.",
 title = "An Empirical Study on Inconsistent Changes to Code Clones at Release Level",
 booktitle = "WCRE '09: Proceedings of the 2009 16th Working Conference on Reverse Engineering",
 year = "2009",
 pages = "85--94",
 publisher = "IEEE Computer Society",
 location = "Lille, France"

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