What does parallel-forms reliability refer to?

Parallel-forms reliability specifically relates to the consistency of results obtained from different versions or forms of the same assessment instrument. This type of reliability is established when two or more forms of a test are created to measure the same construct, and they yield similar outcomes when administered under similar conditions.

The importance of parallel-forms reliability lies in its ability to demonstrate that the assessments can be used interchangeably without significantly affecting the results, thereby ensuring that the test operations remain robust and valid across variations. This is especially crucial in educational settings where assessments may need to be administered in multiple forms to accommodate various conditions, such as testing environments or changes in cohort groups.

By emphasizing this consistency across multiple forms, educators can trust that their assessments reflect students' knowledge or skills fairly, regardless of which version of the test they take.