Secondary task type, exposure frequency, and their combined effects on second language vocabulary learning through reading

The type of processing-resource allocation (TOPRA) model predicts that the semantic processing of new second language (L2) words can impede the learning of their forms while structural processing can promote it. Using this framework, the present study examined the effects of processing type (semantic, structural, control), exposure frequency (one exposure, three exposures), and their combination on the learning of new L2 words through reading. Adult Japanese learners of English read a reading text that contained 10 target words, five of them were repeated only one time whereas the other five were repeated three times. They were asked to answer some comprehension questions as their primary task, and the participants in the semantic and structural processing groups were asked to perform the secondary vocabulary processing tasks (pleasantness rating and phonological recording, respectively) to further process target word meanings or forms. The unexpected first language (L1)-to-L2 and L2-to-L1 cued recall were administered. The positive effects of structural processing and exposure frequency were demonstrated in L1-to-L2 cued recall. The results further suggested that effects of vocabulary processing type and exposure frequency vary depending on how vocabulary gain is measured.