Definitions of Reliability
The quality of a test such that it produces consistent scores.
What is Reliability?
Correlate the scores from a test given at Time 1 with the same test given at Time 2.
What is Test-Retest Reliability?
Observed Score, True Score, and Error Score
What are Test Scores?
Errors within the individual taking the test.
What is Trait Error?
Reliability that examines consistency over time.
What is Test-Retest Reliability?
Examine the percentage of agreement between raters.
The actual score you get on a test.
What is Observed Score?
Errors within the testing situation
A type of reliability that examines the consistency of raters.
What is Inter-Rater Reliability?
Use Cronbach’s alpha to correlate every item with every other item on a test and gives an average correlation among all parts of a test.
What is Internal Consistency Reliability?
The hypothetical score of a person’s real ability / knowledge / skill.
What is True Score?
The difference we’re seeing is due ACTUAL difference and NOT error.
What is Classical Test Theory?
When you want to know if performance on one part of the test is similar to performance on another part of the test.
What is Internal Consistency Reliability?
Correlate the scores from one form of the test with scores from a second form of the test.
What is Parallel Forms Reliability?
The difference between a person’s observed and true score.
What is Error Score?
Observed score = True score + (Trait error score + Method error score)
What Classical Test Theory Equation?
When you want to know if different forms of a test give equivalent scores.
What is Parallel Forms Reliability?