Incidental vocabulary learning in a natural reading context: an eye-tracking study

This study responds to the call for more ecologically valid psycholinguistic research (Spivey & Cardon, 2015) by examining how readers incidentally acquire multifaceted vocabulary knowledge while reading a long, authentic text. Using eye tracking, we explore how the processing of unfamiliar words changes with repeated exposure and how the repeated exposure and processing affect word learning. In two sessions, native and non-native English speakers read five chapters of an authentic English novel containing Dari words. After reading, participants received a comprehension test and three surprise vocabulary tests. Growth curve modeling revealed a non-linear decrease in reading times that followed an S shaped curve. Number of exposures was the strongest predictor of vocabulary learning (form and meaning), while total reading time independently contributed to the learning of word meaning. Thus, both quantity and quality of lexical processing aid incremental vocabulary development and may reveal themselves differently in readers' eye movement records.