Multilevel models are an increasingly popular method to analyze data that originate from a clustered or hierarchical structure. To effectively utilize multilevel models, one must have an adequately large number of clusters; otherwise, some model parameters will be estimated with bias. The goals for this paper are to (1) raise awareness of the…

Educational researchers commonly use the rule of thumb of "design effect smaller than 2" as the justification of not accounting for the multilevel or clustered structure in their data. The rule, however, has not yet been systematically studied in previous research. In the present study, we generated data from three different models…

This paper focuses on the use of the variable race in educational research. Researchers are clearly considered to have the right to choose their variables. But, the use of race in a nonscholarly fashion is held to be professionally inadequate and often detrimental to black Americans. For years, researchers using race to make comparison s between…