The distinguishing characteristics and relationships found among the "Analytical Reading Inventory," the "Durrell Analysis of Reading Difficulty," and the Spache "Diagnostic Reading Scales" in terms of readability levels, oral and silent reading results, and independent and instructional reading levels were examined in a study involving 117 first, second, fourth, and sixth graders. Each student was administered the oral and silent selections of the three tests during a three-day period. The results indicated that, of the three tests, the readability levels of the Spache scales were the most commensurate with the numerical levels specified for the reading selections. However, no significant differences were found in the scores on the oral and silent reading subtest levels of the three tests. (Tables of data, organized by grade level, are appended.) (FL)