reliability of components
the average reliability of scores obtained from the component subsets that make up a test. Components are identified by grouping a large set of items into clusters with similar content through rational or intuitive approaches or through the use of an empirical method (e.g., factor analysis, principal components analysis). The internal consistency of each of the component sets is determined and then used to estimate the overall reliability of the larger test. For example, a researcher might factor analyze a 20-item social support questionnaire, identify three content subscales, calculate the internal consistency of scores for those three subscales, and then use that information to determine the test’s overall reliability.