How to proceed when both normality and sphericity are violated in repeated measures ANOVA
Adjusted F-tests have typically been proposed as an alternative to the F-statistic in repeated measures ANOVA. Despite considerable re-search, it remains unclear how these statistics perform under simultaneous violation of normality and sphericity. Accordingly, our aim here was to conduct a detailed...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universidad de Murcia |
| Repositorio: | DIGITUM. Depósito Digital Institucional de la Universidad de Murcia |
| OAI Identifier: | oai:digitum.um.es:10201/143644 |
| Acceso en línea: | https://doi.org/10.6018/analesps.594291 http://hdl.handle.net/10201/143644 |
| Access Level: | acceso abierto |
| Palabra clave: | Greenhouse-Geisser adjustment Huynh-Feldt adjustment Ajuste Greenhouse-Geisser Ajuste Huynh-Feldt. CDU::1 - Filosofía y psicología::159.9 - Psicología |
| Sumario: | Adjusted F-tests have typically been proposed as an alternative to the F-statistic in repeated measures ANOVA. Despite considerable re-search, it remains unclear how these statistics perform under simultaneous violation of normality and sphericity. Accordingly, our aim here was to conduct a detailed examination of Type I error and power of the F-statistic and the Greenhouse-Geisser (F-GG) and Huynh-Feldt (F-HF) adjustments, manipulating the number of repeated measures (3-6), sample size (10-300), sphericity (Greenhouse-Geisser epsilon estimator, , from its lower to upper limit), and distribution shape (slight to extreme deviations from normality). The findings show that the behavior of F-GGand F-HFdepends on the degree of violation of both normality, sphericity, and sample size. Overall, we suggest using F-GG under violation of sphericity and slight or moderate deviations from normality in all sample size; with severe deviations from both normality and sphericity F-GGmay be used with a sample size larger than 10; and with extreme deviation from both normali-ty and sphericity this statistic may be used with a sample size larger than 30. In the event of discrepant results between F-GGand F-HF, the choice depends on the value. |
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