Internal Consistency

Internal consistency is an umbrella-like term that encompasses several different, but related, procedures used to estimate reliability. Although some do not consider internal consistency, strictly speaking, a type of reliability, it is treated in practice as a reliability estimate and it is common to refer to internal consistency as internal reliability. There are several methods for examining internal consistency, but all methods share two common characteristics. First, they all involve the analysis of data obtained from a single test administered once to a group of examinees. Second, they all involve dividing the targeted test into two or more parts, which are then treated as if they were tests themselves.

There are other reliability estimation approaches that do not involve internal consistency, but instead require correlating different ...