A note on the unbiased estimation of the intraclass correlation

John R. Donoghue, Linda M. Collins

Research output: Contribution to journalArticlepeer-review


The intraclass correlation, ρ, is a parameter featured in much psychological research. Two commonly used estimators of ρ, the maximum likelihood and least squares estimators, are known to be negatively biased. Olkin and Pratt (1958) derived the minimum variance unbiased estimator of the intraclass correlation, but use of this estimator has apparently been impeded by the lack of a closed form solution. This note briefly reviews the unbiased estimator and gives a FORTRAN 77 subroutine to calculate it.

Original languageEnglish (US)
Pages (from-to)159-164
Number of pages6
Issue number1
StatePublished - Mar 1990


  • algorithm
  • hierarchical linear models
  • intraclass correlation
  • unbiased estimation

ASJC Scopus subject areas

  • General Psychology
  • Applied Mathematics


Dive into the research topics of 'A note on the unbiased estimation of the intraclass correlation'. Together they form a unique fingerprint.

Cite this