The effects of different task types on L2 learners' intake and acquisition of two grammatical structures

Recent years have seen a growing interest in the role of tasks in second language acquisition. A substantial body of research now exists investigating the effects of different task types and their accompanying instructions on learning. Less is known about how tasks affect intake and the relationship between intake and acquisition. This study investigated the effects of 1) implicit and explicit inductive instructions and 2) various task types on both intake and acquisition of two English grammatical structures. Fifty adult ESL learners enrolled in private language schools in New Zealand were pretested with the help of a timed and an untimed grammaticality judgement test for prior knowledge of negative adverbs and adverb placement and were randomly assigned to either a dictation, an individual reconstruction, or a collaborative reconstruction treatment. Treatments were accompanied by either implicit instructions (containing only practical instructions on how to perform the task) or explicit instructions (drawing participants’ attention to the target structures and giving an example of them). Performance on the treatments was taken as a measure of intake, and talk-aloud reports were obtained to gauge participants’ awareness during task completion. Gain scores from pretest to posttest and to delayed posttest were taken as an indication of learning effects. The results show that the explicit instructions of the inductive type used in this study were unable to affect participants’ intake and acquisition in comparison with the implicit instructions. Also, the three types of treatments did not have an effect on acquisition in many cases. Where there was an effect, the treatments differentially affected intake and acquisition. Dictation led to high intake, but less acquisition, and the individual reconstruction treatment led to low intake, but greater acquisition. The collaborative reconstruction treatment was the most consistent of the three. The cognitively more demanding reconstruction treatments (i.e. those involving the retention of larger amounts of texts over longer periods of time) resulted in greater acquisition than the dictation treatment. The main theoretical implications of the results are that the type of inductive and lowlevel explicit instructions used in this study were not sufficient to differentially affect intake and acquisition. Other, more explicit types of treatments may be necessary. The results also indicate that task types that are relatively easy, affect intake to a greater extent than more demanding tasks, but that more demanding tasks are more likely to affect acquisition. On a methodological level, the concept of intake was found to be very difficult to operationalise, and it is suggested that additional measures be developed. Finally, the implications for teaching practice are that for relatively complex structures such as negative adverbs and adverb placement exposure to the input with minimal pedagogic intervention may not be sufficient. Teachers may also want to consider the effects of different task types on both intake and acquisition and both teachers and researchers need to be careful in drawing conclusionson the basis of immediate task performance.