Is a reliable test always valid why give an example?
Principles of Assessment Discussed Use only reliable assessment instruments and procedures. Use only assessment procedures and instruments that have been demonstrated to be valid for the specific purpose for which they are being used. Use assessment tools that are appropriate for the target population. Show
What makes a good test?An employment test is considered "good" if the following can be said about it:
Test reliabilityReliability refers to how dependably or consistently a test measures a characteristic. If a person takes the test again, will he or she get a similar test score, or a much different score? A test that yields similar scores for a person who repeats the test is said to measure a characteristic reliably.How do we account for an individual who does not get exactly the same test score every time he or she takes the test? Some possible reasons are the following:
Principle of Assessment: Use only reliable assessment instruments and procedures. In other words, use only assessment tools that provide dependable and consistent information. These factors are sources of chance or random measurement error in the assessment process. If there were no random errors of measurement, the individual would get the same test score, the individual's "true" score, each time. The degree to which test scores are unaffected by measurement errors is an indication of the reliability of the test.Reliable assessment tools produce dependable, repeatable, and consistent information about people. In order to meaningfully interpret test scores and make useful employment or career-related decisions, you need reliable tools. This brings us to the next principle of assessment. Interpretation of reliability information from test manuals and reviewsTest manuals and independent review of tests provide information on test reliability. The following discussion will help you interpret the reliability information about any test.The reliability of a test is indicated by the reliability coefficient. It is denoted by the letter "r," and is expressed as a number ranging between 0 and 1.00, with r = 0 indicating no reliability, and r = 1.00 indicating perfect reliability. Do not expect to find a test with perfect reliability. Generally, you will see the reliability of a test as a decimal, for example, r = .80 or r = .93. The larger the reliability coefficient, the more repeatable or reliable the test scores. Table 1 serves as a general guideline for interpreting test reliability. However, do not select or reject a test solely based on the size of its reliability coefficient. To evaluate a test's reliability, you should consider the type of test, the type of reliability estimate reported, and the context in which the test will be used. Table 1. General Guidelines forReliability coefficient valueInterpretation.90 and upexcellent.80 - .89good.70 - .79adequatebelow .70may have limited applicabilityTypes of reliability estimatesThere are several types of reliability estimates, each influenced by different sources of measurement error. Test developers have the responsibility of reporting the reliability estimates that are relevant for a particular test. Before deciding to use a test, read the test manual and any independent reviews to determine if its reliability is acceptable. The acceptable level of reliability will differ depending on the type of test and the reliability estimate used.The discussion in Table 2 should help you develop some familiarity with the different kinds of reliability estimates reported in test manuals and reviews.
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