Discuss the four methods of estimating reliability.

Question

What will be an ideal response?

Answer 1

Test-retest reliability – assessing how reliable or stable scores on an instrument are over time. For this, participants are tested on same test on two separate occasions. This is useful in situations where performance is expected to remain somewhat stable over time. Important to consider the construct being assessed and how long it is expected to change over time. This is the most commonly used method of reliability.
Alternate forms reliability – assessing stability using different but equivalent versions of a test. For this, individual items are selected from a pool of test questions, both forms should have similar score means, variances, item difficulty, and correlation with other measures. It is best used when the construct being measured is an ability, aptitude, or specific academic skills. Important to consider the construct you are trying to assess, how narrowly defined that construct is, and the breadth and depth of the content domain of that construct from which items need to be developed
Internal consistency – used to determine whether errors associated with content sampling are present. Evaluate individual items to see if those items are consistent with one another and represent a singular construct or trait that is being assessed by the test. There are three primary methods for assessing internal consistency including split-half method, Kuder-Richardson formulas, and Cronbach’s alpha (also referred to as the coefficient alpha) .
Inter-rater reliability – used to assess level of agreement between two or more raters in their evaluation of a particular outcome.