Sentence Depth Measures as Predictors of Reading Difficulty
Walter H. MacGinitie, Richard Tretiak · Reading Research Quarterly · 1971
TWO SUMMARY MEASURES of sentence complexity-depth of postponement and number of levels in a sector analysis-were evaluated as predictors of reading difficulty. Criteria were cloze scores and listed grade level equivalents for 80 of the McCall-Crabbs Standard Test Lessons in Reading. The Lorge Readability Formula was also recalculated, using both the Test Lessons and the Miller-Coleman Readability Scale. The two sentence complexity measures were found to be highly correlated with sentence length and similar to it as predictors of reading difficulty. The revised Lorge Formula is considerably simplified. It omits the ratio of prepositional phrases, which was shown to be an unreliable contributor to prediction when used in combination with vocabulary load and sentence length.