Bilingual learners and some of the many terms for this group

Bilingual learners are a very heterogeneous group, yet they have in common the mastery of two or more languages. The level at which they master their languages can, however, vary greatly. This variation has resulted in the development of several different definitions and terms for bilingualism. Some of the terms are intended to be strictly differentiated from other terms, while others have some overlap.

One way to differentiate between different groups of bilingual learners is the age of acquisition (AoA) of their second language. Examples of applicable terms are simultaneous (2L1 learners/bilingual first children) and sequential bilingual learners, (early bilingual learners and child L2 learners) (Chondrogianni, 2018; Genesee, 2010; Kovelman, Baker, &

Petitto, 2008). According to this categorization, simultaneous bilingual learners, also often referred to as bilingual first children, have two first languages and are regularly exposed from birth to two or more languages (De Houwer, 2009a). In contrast, sequential bilingual learners are bilingual learners who speak one language at home and are introduced to L2 after they are one to two years old through attendance at early childhood education and care (ECEC) institutions (Genesee, 2010).

Early sequential bilingual learners can again be divided into two subgroups, early bilingual learners or child L2 learners. Early bilingual learners are introduced to L2 at a timepoint from birth up to the age of 3 (Kovelman et al., 2008). (Note that this definition implies that some early bilingual learners could also be bilingual first children.) In contrast, a child L2 learner is introduced to L2 after 3-4 years of age and before the age of seven. Thus, these learners have a well-developed L1 (first language) before being introduced to L2.

Another way of differentiating between groups of bilingual learners is the learners’ proficiency level in the two languages. Terms in use here are, for instance, balanced bilingual learners versus second language learners/minority language learners. Balanced bilingualism refers to bilingual learners who master both (all) of their languages equally well (Kohnert & Bates, 2002). In contrast, minority language learners or second language learners refers to children from homes in which a language other than that of the society is the primary spoken language (August & Shanahan, 2006). Note that even though research on minority language learners has often shown that these students lag behind their monolingual peers in the instructional language (Kieffer, 2008;

Mancilla‐Martinez & Lesaux, 2011a; Oller et al., 2007), these definitions simply state that another primary language is spoken at home but do not state how well the children have mastered their second language.

In recent years, the categorization of bilingual learners into different subgroups of learners has been criticized (e.g., sequentially bilingual learners, child L2 learners). One reason for criticizing the categorization of different types of bilingual learners is that such groupings are complex due mainly to the difficulties of creating valid and non-overlapping groups of bilingual children (Genesee, 2010; Luk & Bialystok, 2013). It is also questionable whether the term bilingual can be used as a categorical variable in terms of whether someone is or is not bilingual.

The findings from a confirmatory factor analysis found that the term bilingual is a multi-dimensional construct (Luk & Bialystok, 2013). The construct consisted of how fluent bilingual learners are in their languages, the bilingual learners’ usage of the languages on a daily basis, and the age of onset of active bilingualism. Only by exploring all these dimensions is it possible to fully capture the history, insensitivity and performance of bilingual experience. Most researchers do not explore these dimensions when they define the bilingual participants in their studies as bilingual learners or before they label them by a specific term for a subgroup of bilingual learners. Additionally, from a methodological

view, it is unfortunate to categorize variables that are likely to be continuous (MacCallum, Zhang, Preacher, & Rucker, 2002). Thus, it is recommended that bilingualism should be treated as a continuous variable where the degree of mastering different languages could vary from little to full mastery (Bialystok, 2017). Article 1 in this dissertation explains this understanding of the term bilingual learners in more detail.

This thesis acknowledges the contribution made by this definition to the research field concerning bilingualism and recommends that current and forthcoming research report studies of bilingual learner samples by measuring bilingualism as a continuous construct. However, most of the prior research summarized in this thesis has treated bilingualism as a categorical variable, not a latent continuous variable consisting of different dimensions of bilingualism. The term bilingual learners is therefore used throughout the extended abstract and in the articles not as a continuous multiple construct but as an overall term for bilingual learners in general without including any combined measures of the degree of bilingualism.

Note, however, that the term bilingual is not used consistently throughout the three articles and the extended abstract. The reason is partly that prior research was conducted on specific populations of bilingual learners.

When referencing these studies, the most accurate term for bilingual learners is used to facilitate readers' understanding of when and to which population of bilingual learners these results can be generalized.

Furthermore, article 1 examines a different population of bilingual learners than articles 2 and 3. The populations in articles 2 and 3 partly overlap, and these articles investigate bilingual learners’ language skills at different timepoints in a longitudinal study.

In article 1, the meta-analysis includes the full range of bilingual learners from children who have just started to master their second language to balanced bilingual learners. When searching for articles to include in the Meta-Analysis several terms for bilingual learners were used, yet all the articles that were coded in the meta-analysis referred to bilingual

learners by the term bilingual. The reason could be the name of the theory that most of the identified articles addressed, the bilingual advantage theory. To address this specific research question, the term bilingual learners was most accurate. This article is also the one that comes closest to treating bilingualism as a continuous construct. In this article, the impacts of different bilingual learners’ language experiences are used as separate moderator variables as an alternative to treating bilingualism as a continuous multi-construct variable (De Cat, 2020; Kaushanskaya &

Prior, 2015; Luk & Bialystok, 2013; Unsworth, 2013). Different bilingual language experiences can be regarded as different dimensions of bilingualism. The moderator variables were AoA, the degree of balanced bilingualism (difference in level of L1 and L2 proficiency), and L2 proficiency (difference in L2 level between bilingual and monolingual learners).

The other two articles are based on data from participants in The Stavanger Project. The participants in these studies differ from those investigated in the meta-analysis. In these studies, only data on the children’s level in L2 were available, preventing the possibility of calculating the degree of balanced bilingualism; bilingualism is therefore labelled a categorical variable targeting the children’s low AoA.

In Study 2, the only available information on the children’s bilingual status was that their parents regarded them as bilingual learners and the language(s) spoken at home. We lacked information on the parents’

nationality and could not determine whether parents speaking Norwegian were native Norwegian speakers. We did, however, know that all the bilingual children had been introduced to L2 by at least two years of age. In this article, early bilingual learners are referred to as dual language learners. The term dual language learners refers to children who have acquired two or more languages prior to the age of five (Genesee, 2010). In article 2, dual language learners are often referred to as dual language toddlers, which explicitly means that this

subpopulation of dual language learners was introduced to L2 at an earlier timepoint than 5 years of age.

More sample characteristic information of the bilingual children was available in Study 3, when the children turned 10, due to yet another round of data collection. After the data collection, it was clear that the majority of the bilingual children in Study 3 were bilingual learners from birth, with one minority language-speaking parent and one native Norwegian-speaking parent. The subselection of the sample without a native Norwegian-speaking parent all came from minority language-speaking households. These terms are used in the section of article 3 describing the sample characteristics. However, when the bilingual learners in this article are referred to as a combined group, they are labelled early bilingual learners, which is a more precise description of this subgroup than dual language learners. The switch in terminology from dual language learners to early bilingual learners is also grounded in an adaptation to the terminology used in the papers addressing the theme of article 3.

Finally, to explore whether Bialystok’s claims of poorer language levels but superior EF levels hold across different groups of bilingual learners (Bialystok, 2009, 2017), multiple terms are used for bilingual learners in the discussion of the thesis results. To avoid confusion, however, the term dual language learner was replaced with early bilingual learners in the presentation and discussion of the results in Study 2. This enables one consistent term for the bilingual participants from The Stavanger Project to be used throughout this extended abstract.

2.1.1 First and second languages

All the articles in this thesis include a combination of bilingual children with one native Norwegian-speaking parent and one minority speaking parent and bilingual children with two minority language-speaking parents. This means that for some of the investigated bilingual

learners, the majority language of the society could be the child’s first language (L1); for others, it could be their second language (L2). For simultaneously bilingual learners, both the majority language and the minority language are the child’s first language. To address the bilingual learners’ skills in the different languages at the group level, the children’s skills in the minority language are always referred to as the children’s L1 and the children’s skills in the majority language as their L2. This categorization is carried through the whole thesis regardless of which language the bilingual children actually were first introduced to or were superior in.

2.2 Advantages and disadvantages of