Linguistic Complexity

Despite being the most investigated dimension of L2 performance and proficiency, up to now, complexity has been still vaguely defined and operationalized. The fact is that a number of L2 studies involving complexity have produced mixed and sometimes contradictory results (cf, Robinson 2007; Skehan 2009; Spada & Tomita 2010). These results may be also due to the general definitions given by theorists as, for example, Ellis and Barkhuisen (2005, p. 139) who define complexity as the “use of more challenging and difficult language … Complexity is the extent to which learners produce elaborated language”. In turn, Skehan (2003, p. 8) understands complexity as “the complexity of the underlying interlanguage system developed”. A narrower definition

As the focus of the present study will be the linguistic complexity, a brief definition of the other two will be given here.

According to some researchers (Zaki & Ellis 1999; Ellis & Barkhuizen 2005), propositional complexity is related to the number of information or idea units which a speaker/writer encodes in a given language task to convey a given message content. In turn, discourse-interactional complexity refers to the number and type of turn changes that leanerars initiate and the interactional moves and participation roles that they engage in a conversation. Despite these two components being still relatively new concepts in L2 field, linguistic complexity has been more recurrent in studies involving L2 complexity.

In accordance with Bulté and Housen (2012), L2 literature has classified linguistic complexity in two ways: (1) global or system complexity – a dynamic property of the learner’s L2 system; or (2) local or structure complexity – a more stable property of the individual linguistic items, structures or rules that make up the learner’s L2 system. (Bulté & Housen 2012, p.

Their model proposes a (1) “global elaborateness or systemic complexity of the learner’s L2 phonological system, lexical system, morphological system and so on”, and (2) “local functional and formal complexity of the individual syntactic, morphological, phonological or lexical features that make up the learner’s L2 system” (Bulté and Housen 2012, p. 26).

Bulté and Housen´s model aims to account for the discrepancy among the treatments given to the same linguistic feature in different studies and to fill in the gap for a descriptive analytic framework that can precisely specify the type as well the level of the complexity construct which is being investigated.

Moreover, for the authors above, linguistic complexity can be examined in three different levels: theoretical level, observational level and operational level. On the theoretical level, complexity is analysed as cognitive constructs that encompass the grammatical complexity that is divided in systemic grammatical complexity (elaboration, size, range, variation and ‘breadth’ of L2 grammar) and structural grammatical complexity (depth, embeddness, compositionality of grammatical L2 structures). The observational level corresponds to the surface manifestation of grammatical complexity in L2 performance in various ways and several different levels. On the last level, the