Bulletin of the Psychonomic Society

, Volume 21, Issue 3, pp 213–216 | Cite as

Average correlations vs. correlated averages

  • William P. Dunlap
  • Marshall B. Jones
  • Alvah C. Bittner


When repeated-measures data are collected with small or even moderate sample sizes, correlation matrices show considerable variability. If one’s primary interest is in the correlations, some means of smoothing the coefficients may be desirable. Two methods of smoothing Pearson rs were investigated in the present study. The first method was to average repeated measures in blocks and then correlate block averages. In the second method, all repeated measures were correlated and then the correlation coefficients were averaged in blocks. The latter approach proved much superior, resulting in greatly reduced sampling variability and little distortion in the population correlation estimated.


Average Correlation Effective Sample Size Moderate Sample Size Pursuit Performance Common Index 
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Reference Notes

  1. 1.
    Bittner, A. C., Jr. Averaged correlations between parallel measures: Reliability estimation. Proceedings of the Eighth Psychology in DoD Symposium, USAF Academy, Colorado Springs, Colorado, 1982.Google Scholar
  2. 2.
    Bittner, A. C., Jr., Dunlap, W. P., & Jones, M. B. Averaged cross-correlations with differentially stable variances: Fewer subjects required with repeated measures. Proceedings of the 26th annual meeting of the Human Factors Society, Seattle, Washington, 1982.Google Scholar


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Copyright information

© The Psychonomic Society, Inc. 1983

Authors and Affiliations

  • William P. Dunlap
    • 1
  • Marshall B. Jones
    • 2
  • Alvah C. Bittner
    • 3
  1. 1.Department of PsychologyTulane UniversityNew Orleans
  2. 2.Pennsylvania State University College of MedicineHershey
  3. 3.Naval Biodynamics LaboratoryNew Orleans

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