Although informal reading inventories are widely used, they are not without their shortcomings, regardless of whether they have been published commercially or have been constructed by the teacher. There are at least two significant weaknesses in inventories developed by the teacher: (1) passages selected randomly from the graded basal readers that may or may not be on the level suggested by a publisher, and (2) the types of questions written for them, usually at the memory level of cognition. Published inventories also have their weaknesses, such as the discrepancy between the grade levels assigned to the reading selections by the publishers and their readability levels. Another questionable feature of published inventories is the procedure used for their administration, with students directed to read one selection silently and a different one orally. Because the task of developing a good informal inventory is so complicated, teachers, if they must construct their own, should select several random passages, identify four selections for each grade level from one through ten, and use a modified version of the Fry Readability Graph--extended to determine the difficulty levels of the paragraphs chosen. Introducing teachers to a new format for published inventories is also helpful. Among its new features would be (1) a complete step-by-step procedure for administration, (2) four forms at each grade level, and (3) a readability level for each of the four selections for every grade that is close to the beginning of the grade level for which it is written. (HOD)