Can you explain the two most important properties of tests? (at least 300-400 words)
Let's take a closer look. I also attached a supporting article, which expands on this response, and from which this response is drawn.
1. Can you explain the two most important properties of tests?
Two main properties of psychological tests are reliability and validity. Reliability is "the extent to which a test is repeatable and yields consistent scores" (Essentials of a Good Psychological Test, 2004). For a test to be valid it must be reliable; however, a test can be reliable but not valid (does not measure what it says it measures).
There is a potential for error in all measurement tools. The goal is to minimize this error. Every observed test score is comprised of the true score plus measurement error. Thus, reliability (consistency) is a measure to calculate the amount of the variability in the test scores, and how much is the result of measurement error and how much is the result of variability in true scores. ...
Explains the two most important properties of tests. Supplemented with an informative artcile on the important elements of psychologcial tests. References are provided.