What type of reliability is assessed by the consistency of scores from different items measuring the same construct?

The concept of reliability that pertains to the consistency of scores from different items measuring the same construct is known as internal consistency. This type of reliability evaluates how well the items within a single test correlate with each other, essentially determining whether multiple indicators of the same underlying trait yield similar results.

Internal consistency is crucial because it assures that the items are indeed measuring the same construct and that the test is reliable. Common statistical measures used to assess internal consistency include Cronbach's alpha, where a higher alpha value indicates stronger internal reliability.

In comparison, inter-item reliability is sometimes used interchangeably with internal consistency, but it often refers specifically to the relationship and correlation among items and is a narrower concept within the broader definition of internal consistency. Test-retest reliability assesses how consistent scores are when the same test is administered to the same subjects at two different points in time, while concurrent validity pertains to how well a test correlates with a measure that is taken at the same time.

Thus, the emphasis on various items measuring the same construct and their scoring consistency is distinctly encapsulated in the definition of internal consistency.