The split-half correlation is a statistical measure that assesses the internal consistency of a psychometric test. It is calculated by dividing the test into two halves and correlating the scores of each half. While the term split-half correlation is the most commonly used term, there are several synonyms for this measure, such as Spearman-Brown split-half correlation, reliability coefficient, Cronbach's alpha, and Guttman Split-half reliability. These synonyms are all measures of the degree to which two halves of a test are consistent and reliable in measuring the same construct. The choice of which synonym to use depends on the statistical method used in the analysis and the context in which it is being used.