It is widely believed that subscores can give us more information about an examinee. Thus they can be useful in planning instructional and remedial efforts, or making vocational or academic placement decisions. However, past research has shown that subscores are often not as useful as hoped either because they do not have high reliability or…

Given the relatively high intercorrelations observed between mathematics achievement, reading achievement, and cognitive ability, it has recently been claimed that student assessment studies (e.g., TIMSS, PISA) and intelligence tests measure a single cognitive ability that is practically identical to general intelligence. The present article uses…

Two aspects of the reliability of multidimensional measures can be distinguished: the amount of scale score variance that is accounted for by all underlying factors (composite reliability) and the degree to which the scale score reflects one particular factor (construct reliability). Confidence intervals for composite and construct reliabilities…