VanPatten, B., & Oikkenon, S. (1996). The causative variables in processing instruction: Explanation vs. structured input activities. Studies in Second Language Acquisition.
VanPatten and Oikkenon (1996) conducted this study to find out whether explanation or structured input activities were the causative variables for the previously reported research findings, such as the work by VanPatten and Cadierno (1993).The motivation of this study was derived form the question that processing instruction, like traditional instruction, consists of explanation plus some kind of practice with structured input, and one could conclude that we cannot determine whether or not processing instruction is resulting in a change in the developing system or whether subjects are simply monitoring on the posttest. In short, it may be the Monitor hypothesis by Krashen (1982)[1]
which is major reason for the effects on the studies rather than processing instruction. Then, using the same materials and assessment tasks as used in VanPatten and Cadierno (1993), this study addressed the following research question: “In terms of processing instruction, which of the following appears to be the most significant variable in accounting for pretest/posttest gains: (a) explanation; (b) structured input activities; or (c) explanation and structured input activities combined [=regular processing instruction]?” (VanPatten, 1996, p.121)[2]
. According to this research question, subjects were divided into one of the three groups: (a) Explicit Instruction Only (n=22), (b) Structured Input Activities Only (n=20), or (c) Processing Instruction (n=17).
The statistical analysis revealed that on the interpretation task, the observed effects were caused by both Processing Instruction group and Structured Input Activities Only group, making significant gains from pre- to posttest, whereas Explicit Instruction Only group made no gains. Also, on the production task, the gains made by both Processing Instruction group and Structured Input Activities Only group were greater than those made by Explicit Instruction Only group. From these results, it can be said that the Monitoring is not the causative or significant variable for the results observed in processing instruction. Rather, it is the actual structured input itself and the form-meaning connection being made during input processing that are responsible for the observed effects in the present as well as previous studies.