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…

The present study is an attempt to explore the usefulness of demographic predictors of writing ability. Specifically, it is concerned with delineating the elements involved in writing and to ascertain the effects of achievement, language background, age, sex, social class, etc., on linguistic ability. (Author/RK)