Four readability formulas were analyzed to determine the reading grade equivalence of instructional materials at the middle grades and above: the Dale-Chall formula, the Gunning-Fog Index, the Flesch Reading Ease Formula, and the McLaughlin SMOG Grading. In addition, Spache and Wheeler/Smith formulas were analyzed for evaluating primary grade materials. These analyses showed some problems with the readability formulas, including the following: (1) the formulas ignore much of the current knowledge and theoretical bases of the reading process, (2) they rest on a shaky statistical base, and (3) there is considerable variation in grade level designation for the reading selections. Furthermore, if the readability formulas are based upon the McCall-Crabbs Standard Test Lessons as their criterion for a standard, then the formulas themselves should indicate a difference in the difficulty levels from Books A-D, which they do not to the extent assumed by those who used the lessons as the criterion for the development of their formulas. The conclusions, based upon the findings, are that the readability formulas were based upon unsound criteria, that the correlation research to support the use of other formulas (strength by association) has similar weaknesses, and that the folklore extrapolated from the unfounded assumptions places the question of the use of readability formulas in great jeopardy. (EL)