THE MOVEMENT to measure differentially abilities, skiUs, and various as pects of achievement has gained great impetus from educational and psycholog ical studies conducted during the last two or three decades. Considerable time and study have been devoted to the development of tests which would measure, in relatively pure form, primary mental functions, basic personality traits, differences in performance, preference, and interest. It is natural, then, that we should ask the following question. Can we meas ure specific factors associated with reading comprehension? Logical analysis and thoughtful speculation led many interested students of the reading process to describe reading comprehension in terms of several skills and functions. There seems to be wide agreement among them that reading comprehension can best be described in terms of multiple skills and abilities, rather than as a single or unitary function. Several fundamental questions are raised when we accept the multi-ability description of reading comprehension.