Correcting Measures of Relationship between Aggregate-Level Variables for Both Unreliability and Correlated Errors: An Empirical Example

Ethnic incongruence and the student–teacher relationship: The perspective of ethnic majority teachers

“…First, we aggregated the three original items at the classroom level, and computed Cronbach's α for the 36 classrooms, which was .82. Second, we calculated the reliability coefficient suggested by O'Brien (1998), which indicates the extent to which the mean scores for individual students can be regarded as parallel items of the aggregated measure. This reliability coefficient was sufficient, r = .76.…”