Document Type

Article

Publication Date

2023

DOI

10.20982/tqmp.19.2.p194

Publication Title

Quantitative Methods of Psychology

Volume

19

Issue

2

Pages

194-216

Abstract

Four different bootstrap methods for estimating confidence intervals (CIs) for a coefficient alpha difference from two independent samples (groups) were examined. These four CIs were compared to the most promising non-bootstrap CI alternatives in the literature. All CIs were assessed with a Monte Carlo simulation with conditions similar to previous research. The results indicate that there is a clear order in coverage performance of the CIs. The bootstrapped highest density interval had the best coverage performance across all simulation conditions. Yet, it was impacted by unequal sample sizes when one of the groups had the smallest sample size investigated of 50, or when items came from a compound symmetric correlation matrix with $\rho = 0.64$. Regardless of the simulation condition, the percentile bootstrap is a good alternative as long as both group sample sizes were 200 or more.

Rights

© 2023 The Author.

This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (CC BY 4.0). The use, distribution or reproduction in other forums is permitted, provided the original author(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

Original Publication Citation

Padilla, M. A. (2023). Confidence intervals for the coefficient alpha difference from two independent samples (groups). Quantitative Methods for Psychology, 19(2), 194-216. https://doi.org/10.20982/tqmp.19.2.p194

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