A classroom quasi-experimental study to explore Processing Instruction

Processing Instruction (VanPatten, 1996, 2002a, 2004) contains two types of input activity: Referential activities, which force learners to focus on a form and its meaning, and affective activities, which contain multiple exemplars of the target form but focus learners' attention on the meaning of the sentences in which the form is embedded. To date, these two types of PI activity have been treated as one pedagogical technique, and no study has been empirically conducted to investigate the instructional impact of them individually. Furthermore, whether or not PI activities can promote learners’ implicit knowledge has not been addressed empirically. 120 12-year-old Taiwanese learners of L2 English were quasi-randomly assigned to four groups: Referential + Affective, Referential-only group, Affective-only and a Control. Pre, post and delayed post tests were administered to assess learning of the English 'ed' verb inflection. The measures included three tests aiming to elicit implicit knowledge: A timed grammaticality judgment test, an oral picture narration, and a short structured conversation. Following these tests, a self-report technique was employed to check whether or not learners drew on explicit knowledge. A gap-fill test without a time constraint and a written vocabulary test were also included to examine instructional impact. Findings suggest that referential activities are responsible for the learning gains observed and that the gains are held for up to six weeks after completion of the intervention. However, the issues regarding the role of affective activities in vocabulary learning and PI’s impact on implicit knowledge need further study. An implication of this study is that the claims of previous PI studies regarding the causative factors for its effectiveness require more refined exposition.