Applying FixCache to Code Inspections

Rahman et al. have used a fixcache/bugcache approach to predicting which files should be singled out for code inspection. I have written about using a similair approach for regression test selection (here and here). Their main conclusion is:

When used for inspection, FixCache gets most of its
power by predicting that les that recently experienced
a bug x, do in fact contain additional, latent bugs.

So basically, what they have found is that bugs tend to occur grouped in the same file. I guess there is some profound truth here. But is this just some kind of random statistical property of software artefacts or does it tell us something fundamental about software development?

• [2011,inproceedings] bibtex
  F. Rahman, D. Posnett, A. Hindle, E. Barr, and P. Devanbu, "BugCache for Inspections : Hit or Miss?." 2011.
  @inproceedings{citeulike:9675829,
  author = {Rahman, Foyzur and Posnett, Daryl and Hindle, Abram and Barr, Earl and Devanbu, Premkumar},
  citeulike-article-id = {9675829},
  citeulike-linkout-0 = {http://macbeth.cs.ucdavis.edu/fse2011.pdf},
  keywords = {20110817},
  posted-date = {2011-08-17 10:21:34},
  priority = {0},
  title = {{BugCache} for Inspections : Hit or Miss?},
  url = {http://macbeth.cs.ucdavis.edu/fse2011.pdf},
  year = {2011}
}
• [2010,article] bibtex
  E. Engstrom, P. Runeson, and G. Wikstrand, "An Empirical Evaluation of Regression Testing Based on Fix-Cache Recommendations," Software Testing, Verification, and Validation, 2008 International Conference on, pp. 75-78, 2010.
  @article{citeulike:7426424, abstract = {Background: The fix-cache approach to regression test selection was proposed to identify the most fault-prone files and corresponding test cases through analysis of fixed defect reports. Aim: The study aims at evaluating the efficiency of this approach, compared to the previous regression test selection strategy in a major corporation, developing embedded systems. Method: We launched a post-hoc case study applying the fix-cache selection method during six iterations of development of a multi-million {LOC} product. The test case execution was monitored through the test management and defect reporting systems of the company. Results: From the observations, we conclude that the fix-cache method is more efficient in four iterations. The difference is statistically significant at alpha = 0.05. Conclusions: The new method is significantly more efficient in our case study. The study will be replicated in an environment with better control of the test execution.},
  address = {Los Alamitos, CA, USA},
  author = {Engstrom, Emelie and Runeson, Per and Wikstrand, Greger},
  citeulike-article-id = {7426424},
  citeulike-linkout-0 = {http://doi.ieeecomputersociety.org/10.1109/ICST.2010.40},
  citeulike-linkout-1 = {http://dx.doi.org/10.1109/icst.2010.40},
  doi = {10.1109/icst.2010.40},
  isbn = {978-0-7695-3990-4},
  journal = {Software Testing, Verification, and Validation, 2008 International Conference on},
  keywords = {20110817, 20111003-irop},
  pages = {75--78},
  posted-date = {2010-07-08 01:34:23},
  priority = {0},
  publisher = {IEEE Computer Society},
  title = {An Empirical Evaluation of Regression Testing Based on {Fix-Cache} Recommendations},
  url = {http://dx.doi.org/10.1109/icst.2010.40},
  volume = {0},
  year = {2010}
}
• [2009,inproceedings] bibtex
  G. Wikstrand, R. Feldt, J. K. Gorantla, W. Zhe, and C. White, "Dynamic Regression Test Selection Based on a File Cache—An Industrial Evaluation," in ICST ’09: Proceedings of the 2009 International Conference on Software Testing Verification and Validation, Los Alamitos, CA, USA, 2009, pp. 299-302.
  @inproceedings{citeulike:7426413, abstract = {This paper presents a simple method that computes test case coverage information from information on what files were updated to fix a fault found by the test case. It uses a cache to monitor fault-prone files and recommends test cases to rerun to cover updated files. We present an evaluation of the method during two months of development of a large, industrial, embedded, real-time software system. Our results show that the method is effective, reaching weekly cache hit rates in the range 50-80\%.},
  address = {Los Alamitos, CA, USA},
  author = {Wikstrand, Greger and Feldt, Robert and Gorantla, Jeevan K. and Zhe, Wang and White, Conor},
  booktitle = {ICST '09: Proceedings of the 2009 International Conference on Software Testing Verification and Validation},
  citeulike-article-id = {7426413},
  citeulike-linkout-0 = {http://portal.acm.org/citation.cfm?id=1548215},
  citeulike-linkout-1 = {http://doi.ieeecomputersociety.org/10.1109/ICST.2009.42},
  citeulike-linkout-2 = {http://dx.doi.org/10.1109/icst.2009.42},
  citeulike-linkout-3 = {http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=4815362},
  doi = {10.1109/icst.2009.42},
  isbn = {978-0-7695-3601-9},
  journal = {Software Testing, Verification, and Validation, 2008 International Conference on},
  keywords = {20110817},
  location = {Denver, CO, USA},
  month = apr, pages = {299--302},
  posted-date = {2010-07-08 01:20:26},
  priority = {0},
  publisher = {IEEE Computer Society},
  title = {Dynamic Regression Test Selection Based on a File {Cache—An} Industrial Evaluation},
  url = {http://dx.doi.org/10.1109/icst.2009.42},
  volume = {0},
  year = {2009}
}