how is giftedness related to achievement?; our society has identified two extremes in intelligence. how are these differences identified?; describe the controversy associated with identifying giftedness.; list and explain the three principles of test construction that make a test credible.; describe the differences between achievement tests and aptitude tests.; if a certain test follows a normal curve, most of the scores will fall __________.; a blank test measures what it is supposed to measure; reliable tests are always valid.