RT Journal Article
T1 Repeated measures ANOVA and adjusted F-tests when sphericity is violated: which procedure is best?
A1 Blanca-Mena, María José
A1 Arnau, Jaume
A1 García-Castro, F. Javier
A1 Alarcón-Postigo, Rafael
A1 Bono Cabré, Roser
K1 Psicología - Investigación
K1 Análisis de varianza
AB Introduction: One-way repeated measures ANOVA requires sphericity. Research indicates that violation of this assumption has an important impact on Type I error. Although more advanced alternative procedures exist, most classical texts recommend the use of adjusted F-tests, which are frequently employed because they are intuitive, easy to apply, and available in most statistical software. Adjusted F-tests differ in the procedure used to estimate the corrective factor ε, the most common being the Greenhouse-Geisser (F-GG) and Huynh-Feldt (F-HF) adjustments. Although numerous studies have analyzed the robustness of these procedures, the results are inconsistent, thus highlighting the need for further research.Methods: The aim of this simulation study was to analyze the performance of the F-statistic, F-GG, and F-HF in terms of Type I error and power in one-way designs with normal data under a variety of conditions that may be encountered in real research practice. Values of ε were fixed according to the Greenhouse–Geisser procedure (εˆ). We manipulated the number of repeated measures (3, 4, and 6) and sample size (from 10 to 300), with εˆ values ranging from the lower to its upper limit.Results: Overall, the results showed that the F-statistic becomes more liberal as sphericity violation increases, whereas both F-HF and F-GG control Type I error; of the two, F-GG is more conservative, especially with large values of εˆ and small samples.Discussion: If different statistical conclusions follow from application of the two tests, we recommend using F-GG for εˆ values below 0.60, and F-HF for εˆ  values equal to or above 0.60.
PB Frontiers
YR 2023
FD 2023
LK https://hdl.handle.net/10630/28172
UL https://hdl.handle.net/10630/28172
LA eng
NO Blanca, M. J., Arnau, J., García-Castro, F. J., Alarcón, R., & Bono, R. (2023). Repeated measures ANOVA and adjusted F-tests when sphericity is violated: which procedure is best? Frontiers in Psychology, 14, 1192453. https://doi.org/10.3389/fpsyg.2023.1192453.
NO This research was supported by University of Malaga and grant PID2020-113191GB-I00 from the MCIN/AEI/10.13039/501100011033
DS RIUMA. Repositorio Institucional de la Universidad de Málaga
RD 19 ene 2026