A data analysis strategy is proposed to test for aptitude-by-treatment interactions (ATIs) when treatments are administered to aggregates (e.g., classrooms or other groups) rather than individuals. The strategy satisfies both the statistician's concern for between-unit independence and the ATI researcher's concern for focussing on individual, rather than group, characteristics. In addition, the strategy is shown to be logically and computationally straightforward, while at the same time being capable of detecting ATIs in actual research applications.
ASJC Scopus subject areas
- Developmental and Educational Psychology