01 June 2018

Chakkrit Tantithamthavorn, Surafel Lemma Abebe, Ahmed E. Hassan, Akinori Ihara, and Kenichi Matsumoto

Information and Software Technology (IST)

Context: IR-based bug localization is a classifier that assists developers in locating buggy source code entities (e.g., files and methods) based on the content of a bug report. Such IR-based classifiers have various parameters that can be configured differently (e.g., the choice of entity representation). Objective: In this paper, we investigate the impact of the choice of the IR-based classifier configuration on the top-k performance and the required effort to examine source code entities before locating a bug at the method level. Method: We execute a large space of classifier configuration, 3,172 in total, on 5,266 bug reports of two software systems, i.e., Eclipse and Mozilla. Results: We find that (1) the choice of classifier configuration impacts the top-k performance from 0.44% to 36% and the required effort from 4,395 to 50,000 LOC; (2) classifier configurations with similar top-k performance might require different efforts; (3) VSM achieves both the best top-k performance and the least required effort for method-level bug localization; (4) the likelihood of randomly picking a configuration that performs within 20% of the best top-k classifier configuration is on average 5.4% and that of the least effort is on average 1%; (5) configurations related to the entity representation of the analyzed data have the most impact on both the top-k performance and the required effort; and (6) the most efficient classifier configuration obtained at the method-level can also be used at the file-level (and vice versa). Conclusion: Our results lead us to conclude that configuration has a large impact on both the top-k performance and the required effort for method-level bug localization, suggesting that the IR-based configuration settings should be carefully selected and the required effort metric should be included in future bug localization studies.

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@article{tantithamthavorn2018buglocalization,
    Author={Tantithamthavorn, Chakkrit and Abebe, Surafel L and Hassan, Ahmed E. and Ihara, Akinori and Matsumoto, Kenichi},
    Title = {The Impact of IR-based Classifier Configuration on the Performance and the Effort of Method-Level Bug Localization},
    Booktitle = {Information and Software Technology (IST)},
    page = {In Press},
    Year = {2018}
}