A Study Of Components For Involvement Load Hypothesis In Incidental Second Language Vocabulary Acquisition

Involvement Load Hypothesis (ILH) is composed of three elements facilitating vocabulary acquisition, need, search and evaluation. Each of these three components has certain involvement load. In terms of this hypothesis, language learners'retention of unfamiliar words is conditional upon the degree of involvement while processing target words. The main thesis of this hypothesis,"the higher the level of the involvement load, the more effective the task is in promoting vocabulary acquisition", successfully explained the efficacy of some incidental second language vocabulary acquisition tasks.However, as many researchers pointed out, ILH failed to rule out the influence of time on task on the effectiveness of incidental vocabulary acquisition tasks, thus its feasibility is under suspicion. Moreover, regarding two of the three consisting elements: search and evaluation, two controversial issues are still unsettled by now. (1) Should search and evaluation be assigned the same value of involvement load? Do they contribute similarly to task takers'retention of target words? (2) To what extent, do the facilitative effects of moderate and strong evaluation on task takers'retention of target words differ from each other? Is there any need for the element of evaluation to have two degrees of prominence?With the aim of figuring out these two unsettling issues, this research conducts three comparisons among four common incidental vocabulary acquisition tasks. The first comparison, which is between two tasks with the same involvement index, distribution of the three components and time on task, checks whether the prediction of ILH concerning tasks of the same involvement index and distribution is still feasible with time on task being considered. The second comparison examines whether the two components for this hypothesis: search and evaluation, have similar contribution to task takers'retention of target words. This comparison is between two tasks with the same involvement index and time on tasks. The difference of these two tasks is that one task has an involvement load of 0 for search and 1 for evaluation, while the other has an involvement load of 1 for search but 0 for evaluation. The third comparison, which is among three tasks with the same involvement load of need and search, but one of them has moderate evaluation while the other two have strong evaluation, verifies whether moderate and strong evaluation produce significantly different incidental vocabulary acquisition.These three comparisons mainly produce three findings. Firstly, upon the same time on task, tasks of the same involvement index and distribution of the three components promote similar incidental vocabulary acquisition. Secondly, search is less effective than evaluation in promoting incidental vocabulary acquisition. Thirdly, no significant difference exists between the facilitative effects of strong and moderate evaluation on incidental vocabulary acquisition. With these three empirical findings, this research makes some contribution to the refinement of ILH. Moreover, its pedagogical implications lie in the revelation of advantages and disadvantages of four common instructional programs, and the methodological implications exist in its task designation for the balance of time on task.