Differences in Word Frequency and Length Effects on L2 and L1 Speakers’ Eye Movements

This study analyzes whether word frequency and length effects differ between second language (L2) and first language (L1) speakers. The eye movements of Japanese learners and native speakers of English, specifically first fixation duration and gaze duration during silent reading of English sentences containing target words, were measured. The target words consisted of four categories: long high-frequency words, short high-frequency words, long low-frequency words, and short low-frequency words. The findings revealed that both native and non-native speaker groups demonstrated significantly longer fixations for infrequent words than frequent words in gaze duration. More importantly, the results showed stronger word frequency and length effects for non-native speakers with non-alphabetical L1 than for the native speakers. An additional analysis was conducted by including individual vocabulary sizes to verify the influence on the discrepancy. The analysis showed that the participant’s vocabulary size did not eliminate this differential impact, demonstrating that an additional factor must be involved to explain the difference. The findings posit a significant discrepancy in L1 and L2 single-word processing and require further explanation beyond individual vocabulary sizes.departmental bulletin pape