Note 2 — PART I⁠[1] AN OUTLINE OF THE EXPERIMENT

For scientific purposes we want year-month means and standard deviations, that we may say that Charlie Jones is 2.1 S.D. above the mean for his age level, while Harold Smith is .1 S.D. below that mean. It is in terms such as these that we may be able to compare accomplishment in one function with accomplishment in another, progress in one with progress in another. For many of our problems we need a common denominator of measurement so that we may compare progress between tests and age-groups. The best common denominator is, I believe, S.D. in an age-group. Thus we may locate a child in any age-group in any test and compare that location with the position of any other child in any other test in his age-group.

For practical purposes, however, it is for many reasons more convenient to use quotients in elementary schools. Principals would rather deal with quotients since it is easier to explain them in terms of attainment and capacity. It is the use of such quotients that this thesis discusses.