How to make the test have the qualities of test usefulness I.
Validity It is the extent to which it measures what supposed to measure. The test must aim to provide a true measure of the particular skill which it is intended to measure: to the extent that it measures external knowledge and other skill at the same time, it not is a valid test. About content validity, we should emphasize the face validity and for content validity, the test should be so constructed as to content a representative sample of the course.