Task closure and task complexity effects on L2 written performance

Abstract

Although a major line of task-based research investigates the effects of task condition, little attention has been paid to the differential effects of open vs. closed tasks on L2 learning. Some researchers claim that closed oral interactive tasks are more effective, as the predetermined solution forces learners to continue without giving up, leading to greater negotiation for meaning, language recycling, and provision/incorporation of feedback. Because there is little empirical evidence to support such claims, the present study was conducted to investigate the combined effects of task closure and task complexity on the L2 written performance of 83 Korean learners of English.Participants performed two tasks whose task complexity was operationalized as number of elements. Half of the participants carried out closed task versions, and the other half carried out open versions. Greater task complexity was found to increase cognitive load shown by learner self-ratings, expert judgments, and time-on-task measures. Regarding written performance, greater task complexity had significant effects on lexical diversity and proportion of target-like use of articles. Contrary to previous claims, open tasks were found to elicit greater lexical diversity than closed tasks.