Although proponents of extensive reading (ER) have recommended easy reading material, book difficulty has been poorly defined and operationalized in previous studies. The present study argues for the use of perceived text difficulty for operationalizing book difficulty based on empirical findings (Holster et al., 2017), reading purposes in ER, and…

In second or foreign language (L2) extensive reading (ER) studies, learners have been encouraged to read easy books despite the lack of consensus concerning how to define book difficulty. In light of previous studies reporting that book difficulty can play an important role in learners' affect in ER (e.g., Bahmani & Farvardin, 2017; Chiang,…

This study used many-faceted Rasch measurement to investigate the difficulty of graded readers using a 3-item survey. Book difficulty was compared with Kyoto Level, Yomiyasusa Level, Lexile Level, book length, mean sentence length, and mean word frequency. Word frequency and Kyoto Level were found to be ineffective in predicting students'…