The authors wish to thank Robert Stern, Ralph O'Brien, and Robert Kennedy for their helpful comments.
The Continuing Problem of False Positives in Repeated Measures ANOVA in Psychophysiology: A Multivariate Solution
Article first published online: 30 JAN 2007
Volume 24, Issue 4, pages 479–486, July 1987
How to Cite
Vasey, M. W. and Thayer, J. F. (1987), The Continuing Problem of False Positives in Repeated Measures ANOVA in Psychophysiology: A Multivariate Solution. Psychophysiology, 24: 479–486. doi: 10.1111/j.1469-8986.1987.tb00324.x
A shorter version of this paper was presented at the thirteenth meeting of the Psychophysiology Society, London, December, 1985.
- Issue published online: 30 JAN 2007
- Article first published online: 30 JAN 2007
- (Manuscript received July 14, 1986; accepted for publication January 22, 1987)
- Repeated measures designs;
- Sphericity assumption;
- Multivariate analysis of variance;
- False positives
Violation of the validity assumptions of repeated measures analysis of variance continues to be a problem in psychophysiology. Such violation results in positive bias for those tests involving the repeated measures factor(s), Recently it has been shown that the tests of simple interactions and multiple comparisons are even more vulnerable to bias (Boik. 1981; Mitzel & Games, 1981). The present paper offers a discussion of the validity assumptions for both overall and sub-effect tests and describes a multivariate approach which allows exact analysis of such designs. A modification of the univariate approach is also described. Validity concerns for both approaches are much less problematic than those of the traditional approach.