Abstract.—An experiment was performed to investigate the importance of methodological differences between magnitude estimation and category rating. It was found that the form of a scale varied with(a)the range of responses used by the subject and(b)with his freedom of choosing a highest number. Other factors investigated played a minor role. A narrow range and fixed upper scale value yielded the typical category scale, a wide range with no restriction on the highest value the typical magnitude scale. The same factors that determined the form of the scale also affected the Weber function