Vocabulary size has been recurrently shown to be a good indicator of second language (L2) proficiency. Among the many existing vocabulary tests, the LexTALE test and its equivalents are growing in popularity since they provide for experimental research a rapid (within 5 minutes) and objective way to assess the L2 proficiency of several languages (English, French, Spanish, Chinese, and Italian). In this study, expanding on the standard procedure of test construction in previous Lextale tests, we develop a vocabulary size test for L2 Portuguese proficiency: LextPT. The selected lexical items fall in the same frequency interval in European and Brazilian Portuguese, so that LextPT accommodates both varieties. A large-scale validation study with 452 L2 learners of Portuguese shows that LextPT is not only a sound and effective instrument to measure the L2 lexical knowledge and indicate the proficiency of both European and Brazilian Portuguese, but it is also appropriate for learners with different L1 backgrounds (e.g. Chinese, Germanic, Romance, Slavic). The construction of LextPT, apart from joining the effort to provide a standardized assessment of L2 proficiency across languages, shows that the Lextale tests can be extended to cover different varieties of a language, and that they are applicable to bilinguals with different linguistic experience.
LextPT: A reliable and efficient vocabulary size test for L2 Portuguese proficiencyDespite a considerable amount of research, how to assess second language (L2) proficiency accurately and reliably remains an ongoing question (Hulstijin et al., 2010;Leclercq & Edmonds, 2014). Therefore, different studies commonly resort to various methods to measure it (see Thomas, 1994 andTremblay, 2011 for meta-analysis). The choice of assessment method is usually subject to the researchers' own understanding and to the feasibility (e.g. time limit) in the context of the given study.In the experimental approach to L2 acquisition, wherein participants' L2 proficiency often needs to be assessed rapidly, many studies simply infer it on the basis of information collected through a background questionnaire. For instance, Tremblay (2011) analysed 91 L2 studies that had used a questionnaire-based assessment of L2 proficiency and reported that more than half (55) assigned participants to different proficiency levels conforming to years of L2 instruction (e.g. learners that had learnt the target language for two years and six years, respectively) and institutional status (e.g. first and second-year university students, respectively). This practice has, however, been criticized for being "hopelessly imprecise" (Hulstijin et al., 2010) because learners grouped in these criteria may differ dramatically in terms of cognitive ability, motivation, amplitude, and other factors that constrain L2 acquisition. These differences might lead to highly dissimilar paces of L2 development. In some other studies adopting the questionnaire approach, participants were asked to rate their own L2 ability on a scale (e...