One issue confronting any teacher of reading is the critical problem of the "match." Placing students into an appropriate difficulty level of reading material seems to be an important antecedent of effective reading instruction. Chall and Feldman (1966) explain that teachers' abilities to select appropriate reading materials for children vary and that the accuracy of these selections has a definite effect on achievement.
Miller, J. W. (1979). Teachers' Abilities to Judge the Difficulty of Reading Materials. Reading Horizons: A Journal of Literacy and Language Arts, 19 (2). Retrieved from https://scholarworks.wmich.edu/reading_horizons/vol19/iss2/12