Adapting the Vocabulary Knowledge Scale to measure L3 lexical knowledge

The Vocabulary Knowledge Scale (VKS; Wesche and Paribakht, 1996) is a tool for assessing levels of L2 lexical knowledge. Still, in its original form, it cannot be used in research on L3 acquisition as it does not account for cross-linguistic influences in trilingual students’ vocabulary. Thus, in two studies, we piloted a tool adapted from the VKS, which aimed to activate three languages: L1-Polish, L2-English and L3-Italian (L3-test). In each study, we elicited knowledge of L3-Italian keywords: noncognates, L1-L2-L3 cognates, and L2-L3 cognates. In Study 1, we created four versions of the L3-test, counterbalancing the language of keyword presentation (L1-Polish or L2-English) and instructions (L1-Polish or L2-English). We checked the effectiveness of the four L3-test versions with 58 learners randomly divided into four groups of equal proficiency in L2-English and L3-Italian. The results revealed that the version with keyword presentation in L2-English and instructions in L1-Polish was most effective in eliciting L3-Italian words. In Study 2, we used this L3-test version and tested it with 44 learners of varying L2-English and L3-Italian proficiency. In the paper, we report on the process of tool adaptation and discuss L3 word knowledge (cognates and noncognates) as a function of L2 and L3 proficiency.