Skip to main content

Moving Beyond the Mean: Analyzing Variance in Software Engineering Experiments

  • Conference paper
  • First Online:

Part of the book series: Lecture Notes in Computer Science ((LNPSE,volume 11271))

Abstract

Software Engineering (SE) experiments are traditionally analyzed with statistical tests (e.g., t-tests, ANOVAs, etc.) that assume equally spread data across groups (i.e., the homogeneity of variances assumption). Differences across groups’ variances in SE are not seen as an opportunity to gain insights on technology performance, but instead, as a hindrance to analyze the data. We have studied the role of variance in mature experimental disciplines such as medicine. We illustrate the extent to which variance may inform on technology performance by means of simulation. We analyze a real-life industrial experiment on Test-Driven Development (TDD) where variance may impact technology desirability. Evaluating the performance of technologies just based on means—as traditionally done in SE—may be misleading. Technologies that make developers obtain similar performance (i.e., technologies with smaller variances) may be more suitable if the aim is minimizing the risk of adopting them in real practice.

This is a preview of subscription content, log in via an institution.

Buying options

Chapter
USD   29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD   39.99
Price excludes VAT (USA)
  • Available as EPUB and PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD   54.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Learn about institutional subscriptions

Notes

  1. 1.

    Even though other statistical tests allowing for unequal variances across groups are also available (e.g., the Welch’s t-test, Generalized Least Squares, etc. [11]), they are rarely used to analyze SE experiments [1], and thus, left out of our study.

References

  1. Dybå, T., Kampenes, V.B., Sjøberg, D.I.: A systematic review of statistical power in software engineering experiments. Inf. Softw. Technol. 48(8), 745–755 (2006)

    Article  Google Scholar 

  2. Field, A.: Discovering Statistics Using IBM SPSS Statistics. Sage, London (2013)

    Google Scholar 

  3. Wohlin, C., Runeson, P., Höst, M., Ohlsson, M.C., Regnell, B., Wesslén, A.: Experimentation in Software Engineering. Springer Science & Business Media, New York (2012)

    Chapter  Google Scholar 

  4. Juristo, N., Moreno, A.M.: Basics of Software Engineering Experimentation. Springer Science & Business Media, New York (2001)

    Book  Google Scholar 

  5. Quinn, G.P., Keough, M.J.: Experimental Design and Data Analysis for Biologists. Cambridge University Press, Cambridge (2002)

    Google Scholar 

  6. Cumming, G.: Understanding the New Statistics: Effect Sizes, Confidence Intervals, and Meta-analysis. Routledge, New York (2013)

    Book  Google Scholar 

  7. Borenstein, M., Hedges, L.V., Higgins, J.P., Rothstein, H.R.: Introduction to Meta-Analysis. Wiley, New York (2011)

    MATH  Google Scholar 

  8. Cohen, J.: The earth is round (p \(<\).05). American Psychologist (1994) 997–1003

    Google Scholar 

  9. Kruschke, J.K., Liddell, T.M.: The bayesian new statistics: hypothesis testing, estimation, meta-analysis, and power analysis from a bayesian perspective. Psychon. Bull. Rev. 25(1), 178–206 (2018)

    Article  Google Scholar 

  10. Fritz, C.O., Morris, P.E., Richler, J.J.: Effect size estimates: current use, calculations, and interpretation. J. Exp. Psychol. Gen. 141(1), 2 (2012)

    Article  Google Scholar 

  11. Bates, D., Mächler, M., Bolker, B., Walker, S.: Fitting linear mixed-effects models using lme4. arXiv preprint arXiv:1406.5823 (2014)

  12. Sheskin, D.J.: Handbook of Parametric and Nonparametric Statistical Procedures. CRC Press, Boca Raton (2003)

    Google Scholar 

  13. Nakagawa, S., et al.: Meta-analysis of variation: ecological and evolutionary applications and beyond. Methods Ecol. Evol. 6(2), 143–152 (2015)

    Article  Google Scholar 

  14. Senior, A.M., Gosby, A.K., Lu, J., Simpson, S.J., Raubenheimer, D.: Meta-analysis of variance: an illustration comparing the effects of two dietary interventions on variability in weight. Evol. Med. Public Health 2016(1), 244–255 (2016)

    Article  Google Scholar 

  15. Stevens, S.L., et al.: Blood pressure variability and cardiovascular disease: systematic review and meta-analysis. bmj 354 (2016) i4098

    Google Scholar 

  16. Senior, A., Nakagawa, S., Raubenheimer, D., Simpson, S., Noble, D.: Dietary restriction increases variability in longevity. Biol. Lett. 13(3), 20170057 (2017)

    Article  Google Scholar 

  17. Gelman, A., Carlin, J.B., Stern, H.S., Rubin, D.B.: Bayesian Data Analysis. vol. 2. Taylor & Francis, Boca Raton (2014)

    Google Scholar 

  18. Brown, M.B., Forsythe, A.B.: Robust tests for the equality of variances. J. Am. Stat. Assoc. 69(346), 364–367 (1974)

    Article  Google Scholar 

  19. Erdogmus, H., Morisio, M., Torchiano, M.: On the effectiveness of the test-first approach to programming. IEEE Trans. Softw. Eng. 31(3), 226–237 (2005)

    Article  Google Scholar 

  20. Kitchenham, B., Madeyski, L., Budgen, D., Keung, J., Brereton, P., Charters, S., Gibbs, S., Pohthong, A.: Robust statistical methods for empirical software engineering. Empir. Softw. Eng. 22(2), 579–630 (2017)

    Article  Google Scholar 

  21. Vickers, A.J.: Parametric versus non-parametric statistics in the analysis of randomized trials with non-normally distributed data. BMC Med. Res. Methodol. 5(1), 35 (2005)

    Article  Google Scholar 

  22. Norman, G.: Likert scales, levels of measurement and the laws of statistics. Adv. Health Sci. Educ. 15(5), 625–632 (2010)

    Article  Google Scholar 

  23. Dieste, O., Fernández, E., Garcia Martinez, R., Juristo, N.: Comparative analysis of meta-analysis methods: when to use which? In: 15th Annual Conference on Evaluation & Assessment in Software Engineering (EASE 2011), IET, pp. 36–45 (2011)

    Google Scholar 

Download references

Acknowledgments

This research was developed with the support of the Spanish Ministry of Science and Innovation project TIN2014-60490-P.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Adrian Santos .

Editor information

Editors and Affiliations

Rights and permissions

Reprints and permissions

Copyright information

© 2018 Springer Nature Switzerland AG

About this paper

Check for updates. Verify currency and authenticity via CrossMark

Cite this paper

Santos, A., Oivo, M., Juristo, N. (2018). Moving Beyond the Mean: Analyzing Variance in Software Engineering Experiments. In: Kuhrmann, M., et al. Product-Focused Software Process Improvement. PROFES 2018. Lecture Notes in Computer Science(), vol 11271. Springer, Cham. https://doi.org/10.1007/978-3-030-03673-7_13

Download citation

  • DOI: https://doi.org/10.1007/978-3-030-03673-7_13

  • Published:

  • Publisher Name: Springer, Cham

  • Print ISBN: 978-3-030-03672-0

  • Online ISBN: 978-3-030-03673-7

  • eBook Packages: Computer ScienceComputer Science (R0)

Publish with us

Policies and ethics