In an attempt to score a test against a norm without losing track of the difficulty of the test material, Educational Testing Service has sought items whose characteristics have been empirically determined rather than left to the individual judgments of teachers and test writers. Separate scales were established to measure different academic abilities by aligning the test takers on a scale of proficiency on that ability and determining strata of ability such that differences within strata were relatively small. If a large number of people can be sorted into strata so that the curves for a large number of items on some mental function are all normal ogives, then the items are scalable. Results of a preliminary tryout on 1,000 SAT test takers were analyzed successfully using this technique. It is concluded that an individual's scale value on such a test can be found, though the procedure involves considerable computational labor and would not be generally usable outside of an experimental situation.