Biofeedback and Self-regulation

, Volume 17, Issue 2, pp 153–156 | Cite as

The effect of influential outliers on parameter estimation in regression analysis

  • John P. Hatch
  • Thomas J. Prihoda
Technical Comments


A comment is made on an article recently published in this journal by Borgeat, Elie, and Castonguay (1991). It is noted that the raw data contained an outlier which is shown to have had a large influence on their estimation of the regression coefficient. Analysis of the data using a nonparametric statistic that is optimal for long-tailed distributions showed that the true regression coefficient is probably smaller than that reported. Other approaches to the analysis of data containing influential outliers are discussed.

Descriptor Key Words

influential observations data analysis regression analysis statistics 


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  1. Belsley, D. A., Kuh, E., & Welsch, R. E. (1980).Regression diagnostics: Identifying influential data and sources of colinearity. New York: John Wiley.Google Scholar
  2. Borgeat, F., Elie, R., & Castonguay, L. G. (1991). Muscular response to the therapist and symptomatic improvement during biofeedback for tension headache.Biofeedback & Self-Regulation, 16 147–155.Google Scholar
  3. Brogan, D. R., & Kutner, M. H. (1980). Comparative analysis of pretest-posttest research designs.The American Statistician, 34 229–232.Google Scholar
  4. Cook, R. D. (1977). Detection of influential observations in linear regression.Technometrics, 19 15–18.Google Scholar
  5. Hollander, M., & Wolfe, D.A. (1973).Nonparametric statistical methods. New York: John Wiley.Google Scholar
  6. Mosteller, F., & Tukey, J. W. (1977).Data analysis and regression: A second course in statistics. Reading, MA: Addison-Wesley, Chap. 14.Google Scholar

Copyright information

© Plenum Publishing Corporation 1992

Authors and Affiliations

  • John P. Hatch
    • 1
  • Thomas J. Prihoda
    • 1
  1. 1.Department of PsychiatryThe University of Texas Health Science Center at San AntonioSan Antonio

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