Volume 45, Issue 3

In this paper we describe a taxonomy of task demands which distinguishes between Task Complexity, Task Condition and Task Difficulty. We then describe three theoretical claims and predictions of the Cognition Hypothesis (Robinson 2001, 2003b, 2005a) concerning the effects of task complexity on: (a) language production; (b) interaction and uptake of information available in the input to tasks; and (c) individual differences-task interactions. Finally we summarize the findings of the empirical studies in this special issue which all address one or more of these predictions and point to some directions for continuing, future research into the effects of task complexity on learning and performance.

Attention to a task, and the language it requires to be performed, can be described in relation to two theoretical models which have prompted research into the effects of task demands on learning and performance outside the field of second language acquisition (SLA). These are the SEEV (selection, effort, expectancy and value) model of selective attention, and the Multiple Resources Model of divided attention to task demands. This paper describes these models, and some of their implications for research into the effects of second language task demands on speech performance and SLA.

Three interactive tasks, increasing in the complexity of resource-directing reasoning demands on speaker/storyteller attribution of, and linguistic reference to, the thoughts and intentions of characters in narrative stimuli were performed by Japanese L1 speakers of English. Largely consistent with the claims of the Cognition Hypothesis, results of the present study show; (i) task complexity led to more complex speech assessed using specific measures motivated by the conceptual/linguistic demands of the tasks but did not, however, affect accuracy, fluency and complexity assessed using general measures; (ii) tasks requiring complex reasoning about characters' intentional states led to significantly more interaction, and uptake of premodified input than simpler versions; and (iii) output processing anxiety showed a linearly progressive, negative relationship to use of complex speech as tasks increased in complexity. The role of specific versus general measures of production is discussed, as is the importance of examining interactions of production, interaction and uptake with measures of individual differences when researching the influence of L2 task demands on learning and performance.

This paper analyses the effects of manipulating the cognitive complexity of L2 oral tasks on language production. It specifically focuses on self-repairs, which are taken as a measure of accuracy since they denote both attention to form and an attempt at being accurate. By means of a repeated measures design, 42 lower-intermediate students were asked to perform three different tasks types (a narrative, and instruction-giving task, and a decision-making task) for which two degrees of cognitive complexity were established. The narrative task was manipulated along +/− Here-and-Now, an instruction-giving task manipulated along +/− elements, and the decision-making task which is manipulated along +/− reasoning demands. Repeated measures ANOVAs are used for the calculation of differences between degrees of complexity and among task types. One-way ANOVA are used to detect potential differences between low-proficiency and high-proficiency participants. Results show an overall effect of Task Complexity on self-repairs behavior across task types, with different behaviors existing among the three task types. No differences are found between the self-repair behavior between low and high proficiency groups. Results are discussed in the light of theories of cognition and L2 performance (Robinson 2001a, 2001b, 2003, 2005, 2007), L1 and L2 language production models (Levelt 1989, 1993; Kormos 2000, 2006), and attention during L2 performance (Skehan 1998; Robinson, 2002).

This study puts the Cognition Hypothesis (Robinson 2005) to the test with respect to its predictions of the effects of changes in task complexity (± few elements) and task condition (± monologic) on L2 performance. 44 learners of Dutch performed both a simple and a complex oral task in either a monologic or a dialogic condition. The performance of the L2 learners was analysed with regard to linguistic complexity, accuracy, and fluency. As predicted by the Cognition Hypothesis, the complex task generated more accurate though less fluent speech. Linguistic complexity, however, was only marginally affected. Dialogic tasks triggered more accurate and fluent output though it was structurally less complex. The interaction of task complexity and task condition showed effects on measures of accuracy only: in the monologic but not in the dialogic condition task complexity did promote accuracy. As a consequence, our results only partially support the Cognition Hypothesis.

In a study on L2 proficiency in writing, conducted among 84 Dutch university students of Italian and 75 students of French, manipulation of task complexity led in the complex task to a significant decrease of errors, while at the same time a trend for a lexically more varied text was observed (Kuiken and Vedder 2005, 2007, in press). Based on this first analysis in which some global performance measures were used, a more specific analysis was carried out. In the latter analysis, which is reported in this article, accuracy was investigated in more detail according to the type of errors in the L2 texts, while lexical variation was analysed further by distinguishing frequent words from infrequent ones. Results showed that the effect of task complexity could mainly be attributed to lower ratios of lexical errors in the more complex task. With respect to the use of frequent versus infrequent words mixed results were found. On the basis of these findings a number of implications with regard to the operationalisation of task complexity and linguistic performance are discussed.