A procedure is described for rescaling objective measures of comprehension so that they reflect amounts of accuracy of comprehension on an absolute scale. The procedure is based upon rauding theory, a theory that interrelates reading ability, passage difficulty, reading time, and passage comprehension. The validity of the rescaling procedure is dependent upon one primary assumption-that the relationship between the objective measure of comprehension and the theoretical construct, accuracy of comprehension, is linear. The rescaling procedure was evaluated and illustrated by application to previously collected data. Four different measures of passage comprehension administered subsequent to reading yielded drastically different "percent comprehension" scores-the average of all the errors among the measures at each rate was 15%. However, when the four measures were rescaled, all four provided accuracy of comprehension scores which were more similar-the corresponding average of all these errors was only 6%. There appears to be adequate empirical evidence supporting the validity of the rauding rescaling procedure. It represents a method for measuring reading comprehension on a ratio scale with absolute units rather than the relative units now being used.
29