Equivalence Test and Sample Size Procedures for Standardized Mean Differences in ANCOVA Studies

Gwowen Shieh

Journal of Probability and Statistics, 2025, vol. 2025, 1-11

Abstract: This article presents exact equivalence tests of standardized mean differences in ANCOVA studies. As an alternative to the traditional hypothesis testing for confirming the existence of substantial differences, the proposed equivalence procedure helps appraise whether the target effect is practically identical to a meaningful magnitude or a trivial value. The general formulation of standardized mean differences permits a wide range of research hypotheses to be examined, including the contrast effect for treatment comparisons and the interaction effect in factorial designs. The associated power and sample size formulas are also described to accommodate the stochastic features of response and covariate variables. The usefulness and applicability of the suggested techniques are illustrated with two examples for the comparison of intervention effects and the assessment of training interactions. Extensive empirical investigations demonstrate the importance of random features and disparity of covariate variables in power and sample size calculations.

Date: 2025
References: Add references at CitEc
Citations:

Downloads: (external link)
http://downloads.hindawi.com/journals/jps/2025/5557130.pdf (application/pdf)
http://downloads.hindawi.com/journals/jps/2025/5557130.xml (application/xml)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:hin:jnljps:5557130

DOI: 10.1155/jpas/5557130

Access Statistics for this article

More articles in Journal of Probability and Statistics from Hindawi
Bibliographic data for series maintained by Mohamed Abdelhakeem ().