A Systematic Review of Eye-Tracking Technology in Second Language Research

Eye-tracking has become increasingly popular in second language (L2) research. In this study, we systematically reviewed 111 eye-tracking studies published in 17 L2 journals to explore the application and replicability of eye-tracking technology in L2 research. The results revealed eight areas of application of eye-tracking in L2 research, among which grammar and vocabulary were the most frequently examined lines of inquiry. We also identified three types of cognitive mechanisms investigated in L2 eye-tracking studies: attention, higher cognitive processes, and cognitive load. Attention was predominantly measured via fixation temporal indices, while higher cognitive processes were frequently measured by using fixation count and fixation temporal measures. In addition, the measures adopted to assess cognitive load mainly depended on the task type. Finally, with respect to the replicability of the studies, transparent reporting practices were evaluated based on 33 features of replicable studies. We found that more than 95% of the reviewed studies reported less than 70% of the information essential for future replication studies. We suggest that the reporting of the information critical to conducting replicable L2 eye-tracking research needs improvement in transparency and completeness. The implications of this study are discussed.