The BEST Dataset of Language Proficiency

Researchers investigating processes stemming from or related to multilingualism often face the challenge of correctly characterizing their multilingual samples in terms of language use, proficiency, dominance, and exposure. This is typically done by using a variety of objective (e.g., normed tests) and/or subjective (e.g., self-reports) measures which tend to vary largely across laboratories and studies, since to date the existence of a comprehensive set of measures and norms is limited to certain language combinations (see Gollan et al., 2012). The current study provides a compelling dataset of norms obtained from a large number of Spanish–Basque–English multilinguals from the Basque Country that will facilitate participant selection and classification as a function of their background and language skills. Contrary to Spanish and English, the Basque language is not a member of the Indo-European language family. It is widely used within the autonomous communities of the Basque Country and Navarra, both located in northern Spain, as well as in the French Pyrénées-Atlantiques. The current study focuses on multilinguals living in the Spanish autonomous community of the Basque Country, an area containing a wealth of bilingual speakers of Spanish and Basque, the two co-official languages, who also know English as a foreign language to a certain extent. Many Basque adults grew up speaking Basque and/or Spanish at home and subsequently received education in one or both of these languages. Additionally, English has been taught as part of the Spanish academic curriculum from the early 1970s, and nearly everyone in the Basque Country below the age of 50 has been exposed to English at school. For this reason, the majority of young and middle-aged Basque adults are better characterized as multilinguals than as bilinguals solely. However, this multilingual population’s knowledge of languages is not homogeneous. While some multilinguals are Spanish dominant, others use Spanish and Basque in a more balanced way or are more dominant in Basque. Furthermore, the exposure to and proficiency in English varies greatly. The complex linguistic reality of the Basque Country provides researchers with an ideal environment to investigate aspects related to multilingualism. For this reason, recent years have witnessed an exponential increase in the number of psycholinguistic studies on Basque bi-/multilinguals exploring semantic (e.g., Perea et al., 2008), syntactic (e.g., Díaz et al., 2016), lexical (e.g., Duñabeitia et al., 2010b), and ortho-phonological processes (e.g., Casaponsa et al., 2015). Besides, recent studies have also focused on Basque multilinguals in order to explore language-mediated domain-general cognitive processes such as attention (e.g., see Antón et al., 2014, 2016; Duñabeitia et al., 2014) or learning (e.g., Cenoz, 1998). Given this increased presence of studies with Basque multilinguals, some efforts have been made to provide researchers with databases that allow for the creation of adequately characterized research materials (e.g., Perea et al., 2006; Duñabeitia et al., 2010a; Acha et al., 2014).