The validity of the test refers to the standard – how much our test differs from it. On the otherside test validity indicates whether the test measures the ability we ourselves want to measure. For example if we want to measure speed, a 30 meter maximal run time with flying start would have a very high validity. However, if we want to measure speed with 30 meter maximal run time using regular start it has much less validity, because initial acceleration has probalby higher component in the final time. Therefore, using the second test we do not measure speed, but a complex of acceleration and speed. If we now conclude that the speed of the runner is low, it might not be the speed that is low, but the initial acceleration ability. Validity is generally considered as the most important factor of the performance testing. If you loose validity – you do not measure what you want or intend to measure.
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