the most complex criterion 最复杂的标准By observation and theoretical justification, “There is no final, absolute, and objective measure of validity.” We have to ask questions that yield convincing evidence that a test accurately and sufficiently measures the testee for the particular purpose of the test. Validity is by far the most complex criterion of a good test. To measure writing ability, one might ask students to write as many words as they can in 15 minutes. Then count the words for the final score. The test would be practical, reliable and easy to administer, and the scoring should be quite dependable. However, it would hardly constitute a valid test of writing ability unless some considerations were given to communication and organization of ideas among other factors.