Skip to main content
Log in

Alpha, Dimension-Free, and Model-Based Internal Consistency Reliability

  • Theory and Methods
  • Published:
Psychometrika Aims and scope Submit manuscript

Abstract

As pointed out by Sijtsma (in press), coefficient alpha is inappropriate as a single summary of the internal consistency of a composite score. Better estimators of internal consistency are available. In addition to those mentioned by Sijtsma, an old dimension-free coefficient and structural equation model based coefficients are proposed to improve the routine reporting of psychometric internal consistency. The various ways to measure internal consistency are also shown to be appropriate to binary and polytomous items.

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

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Bentler, P. M. (1964). Generalized classical test theory error variance. American Psychologist, 19, 548.

    Google Scholar 

  • Bentler, P. M. (1968). Alpha-maximized factor analysis (Alphamax): Its relation to alpha and canonical factor analysis. Psychometrika, 33, 335–345.

    Article  PubMed  Google Scholar 

  • Bentler, P. M. (1972). A lower-bound method for the dimension-free measurement of internal consistency. Social Science Research, 1, 343–357.

    Article  Google Scholar 

  • Bentler, P. M. (2003, July). Should coefficient alpha be replaced by model-based reliability coefficients? Invited paper presented at International Meetings of the Psychometric Society, Cagliari, IT.

  • Bentler, P. M. (2007). Covariance structure models for maximal reliability of unit-weighted composites. In S.-Y. Lee (Ed.), Handbook of latent variable and related models (pp. 1–19). Amsterdam: North-Holland.

    Chapter  Google Scholar 

  • Bentler, P. M. (in press). EQS 6 structural equations program manual. Encino: Multivariate Software. www.mvsoft.com.

  • Bentler, P. M., & Kano, Y. (1990). On the equivalence of factors and components. Multivariate Behavioral Research, 25, 67–74.

    Article  Google Scholar 

  • Bentler, P. M., & Woodward, J. A. (1980). Inequalities among lower bounds to reliability: With applications to test construction and factor analysis. Psychometrika, 45, 249–267.

    Article  Google Scholar 

  • Bollen, K. A. (1980). Issues in the comparative measurement of political democracy. American Sociological Review, 45, 370–390.

    Article  Google Scholar 

  • della Riccia, G., & Shapiro, A. (1982). Minimum rank and minimum trace of covariance matrices. Psychometrika, 47, 443–448.

    Article  Google Scholar 

  • Heise, D. R., & Bohrnstedt, G. W. (1970). Validity, invalidity, and reliability. In E. F. Borgatta (Ed.), Sociological methodology 1970 (pp. 104–129). San Francisco: Jossey-Bass.

    Google Scholar 

  • Jöreskog, K. G. (1971). Statistical analysis of sets of congeneric tests. Psychometrika, 36, 109–133.

    Article  Google Scholar 

  • Kano, Y., & Azuma, Y. (2003). Use of SEM programs to precisely measure scale reliability. In H. Yanai, A. Okada, K. Shigemasu, & Y. Kano (Eds.), New developments in psychometrics (pp. 141–148). Tokyo: Springer.

    Google Scholar 

  • Lee, S.-Y., Poon, W.-Y., & Bentler, P. M. (1995). A two-stage estimation of structural equation models with continuous and polytomous variables. British Journal of Mathematical and Statistical Psychology, 48, 339–358.

    PubMed  Google Scholar 

  • Li, L., & Bentler, P. M. (2004). The greatest lower bound to reliability: Corrected and resampling estimators. Paper presented at Symposium on Recent Developments in Latent Variables Modeling. Tokyo: Japanese Statistical Association and Japanese Behaviormetric Society.

  • McDonald, R. P. (1985). Factor analysis and related methods. Hillsdale: Erlbaum.

    Google Scholar 

  • McDonald, R. P. (1999). Test theory: A unified treatment. Mahwah: Erlbaum.

    Google Scholar 

  • Muthén, B. (1984). A general structural equation model with dichotomous, ordered categorical, and continuous latent variable indicators. Psychometrika, 49, 115–132.

    Article  Google Scholar 

  • Raykov, T. (2001). Bias of coefficient α for fixed congeneric measures with correlated errors. Applied Psychological Measurement, 25, 69–76.

    Article  Google Scholar 

  • Shapiro, A. (1982). Rank reducibility of a symmetric matrix and sampling theory of minimum trace factor analysis. Psychometrika, 47, 187–199.

    Article  Google Scholar 

  • Shapiro, A., & ten Berge, J. M. F. (2000). The asymptotic bias of minimum trace factor analysis, with applications to the greatest lower bound to reliability. Psychometrika, 65, 413–425.

    Article  Google Scholar 

  • Sijtsma, K. (in press). On the use, the misuse, and the very limited usefulness of Cronbach’s alpha. Psychometrika. doi:10.1007/s11336-008-9101-0.

  • ten Berge, J. M. F., & Sočan, G. (2004). The greatest lower bound to the reliability of a test and the hypothesis of unidimensionality. Psychometrika, 69, 613–625.

    Article  Google Scholar 

  • ten Berge, J. M. F., Snijders, T. A. B., & Zegers, F. E. (1981). Computational aspects of the greatest lower bound to reliability and constrained minimum trace factor analysis. Psychometrika, 46, 201–213.

    Article  Google Scholar 

  • Woodhouse, B., & Jackson, P. H. (1977). Lower bounds for the reliability of a test composed of nonhomogeneous items II: A search procedure to locate the greatest lower bound. Psychometrika, 42, 579–591.

    Article  Google Scholar 

  • Woodward, J. A., & Bentler, P. M. (1978). A statistical lower-bound to population reliability. Psychological Bulletin, 85, 1323–1326.

    Article  PubMed  Google Scholar 

  • Zinbarg, R. E., Revelle, W., Yovel, I., & Li, W. (2005). Cronbach’s α, Revelle’s β, and McDonald’s ω H : Their relations with each other and two alternate conceptualizations of reliability. Psychometrika, 70, 1–11.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Peter M. Bentler.

Additional information

Research supported in part by grants DA00017 and DA01070 from the National Institute on Drug Abuse. This paper is based in part on Bentler (2003).

Rights and permissions

Reprints and permissions

About this article

Cite this article

Bentler, P.M. Alpha, Dimension-Free, and Model-Based Internal Consistency Reliability. Psychometrika 74, 137–143 (2009). https://doi.org/10.1007/s11336-008-9100-1

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11336-008-9100-1

Keywords

Navigation