Effect Size Measures and Sample Size Determination in Multilevel Mediation Analysis within the Structural Equation Modeling Framework

This study aims to investigate the sample size requirement for the multilevel mediation model. The study is divided into three parts. Part I will investigate the effect size measures for multilevel mediation effect, benchmarking other existing measures for multilevel modeling. Effect size is one factor that affects the adequacy of sample size. The results of Part I will enhance researchers’ understanding of the effect size and help to anticipate the effect size of the study prior to data collection. In Part II, simulation studies will be conducted to systematically evaluate the performance of the multilevel mediation model at varying sample sizes within the multilevel structural equation modeling framework and formulate some rules governing sample size determination in the multilevel mediation context. In Part III, a R-based program for sample size and effect size computation for multilevel mediation analysis will be developed based on the results of Parts I and II. This study will help researchers to determine an optimal sample size for multilevel mediation analysis in face of resource limitation and will contribute to improving the study design for mediation with multilevel data and enhancing the methodological rigor of research studies.

Funding Source: RGC - General Research Fund (GRF)