On a test designed to measure knowledge of American History, this question becomes completely invalid. It becomes less valid as a measurement of advanced addition because as it addresses some required knowledge for addition, it does not represent all of knowledge required for an advanced understanding of addition. The test question “1 + 1 = _” is certainly a valid basic addition question because it is truly measuring a student’s ability to perform basic addition. Validity refers to the degree in which our test or other measuring device is truly measuring what we intended it to measure. After all, we are relying on the results to show support or a lack of support for our theory and if the data collection methods are erroneous, the data we analyze will also be erroneous. Just as we would not use a math test to assess verbal skills, we would not want to use a measuring device for research that was not truly measuring what we purport it to measure. Whenever a test or other measuring device is used as part of the data collection process, the validity and reliability of that test is important.

Clinical psychologists generally regard them as having sufficient statistical validity for many clinical purposes.Share Tweet Share tumblr reddit Test Validity and Reliability Another description is there is a 95% chance the true IQ is in range from four to five points above to four to five points below the test IQ, depending on the test in question. For modern tests, the standard error of measurement is about three points, or in other words, the odds are about two out of three that a person's true IQ is in range from three points above to three points below the test IQ. A test-taker's score on any one IQ test is surrounded by an error band that shows, to a specified degree of confidence, what the test-taker's true score is likely to be.

A high reliability implies that while test-takers can have varying scores on differing occasions when taking the same test and can vary in scores on different IQ tests taken at the same age, the scores generally agree. Psychometricians generally regard IQ tests as having high statistical reliability. (IQ score table data and pupil pseudonyms adapted from description of KABC-II norming study cited in Kaufman 2009.) Pupil Reliability and Validity IQ scores can differ to some degree for the same individual on different IQ tests (age 12–13 years).

Iq test reliability and validity