A Study Of The Effects Of Task Involvement Load On L2 Incidental Vocabulary Learning

Vocabulary acquisition is an essential element in the process of learning a foreign language and language ability largely depends on how well learners can use appropriate words to convey meanings. Since the 1990’s, in response to the limitations of learning by rote, a growing amount of studies about the effectiveness of incidental learning of vocabulary through listening, writing and reading has been published. Among these incidental strategies, reading is claimed to be particularly conducive to the development of vocabulary knowledge(Hulstijn & Laufer, 2001; Xu, 2010). However, further researches point out that reading alone cannot meet the demands of vocabulary acquisition, and that contextualized and meaningful tasks should be designed on pre or post reading to compensate for its limitations(Beal, 2007; Keating, 2008).Hulstijn & Laufer(2001) did an empirical study about the effectiveness of such tasks and proposed the ‘involvement load hypothesis’, which claims that the greater the involvement load in a task, the better the retention of vocabulary will be, and suggests that tasks with high involvement load be used in vocabulary learning. The present study aims to probe the effectiveness of the involvement load hypothesis from the perspectives of task frequency and components distribution of tasks. Two experiments were conducted in the study with 92 participants from two grade one classes in a university in Suzhou. From the perspective of components distribution of tasks, the first experiment investigates the effectiveness of two output tasks with the same involvement load but different distributions of components in the initial learning and retention of vocabulary between learners of different proficiency levels. The second experiment probes the hypothesis from the perspective of task frequency by comparing two combined tasks with one reinforced task(with both the former and the latter having the same overall involvement load). The participants from each intact class were divided into two groups with higher and lower proficiency levels before taking part in the two experiments, and were given an unexpected vocabulary test named Vocabulary Knowledge Scale(VKS) immediately after they read the same text and finished the post-reading output tasks. Both groups in each intact class then took the same test two weeks later to measure their retention of vocabulary learning. The major findings of this study are that two tasks with the same involvement load but different distributions of components induce the same learning effects in the initial learning and retention of vocabulary. Furthermore, one reinforced task has a better learning effect than two tasks combined with the same total involvement load. Finally, when the assigned post-reading task is too difficult to be handled for both levels of learners, lower-level participants have nearly the same learning effects as higher-level participants. However, when the given task is with some difficulty to produce data that distinguishes between the learning levels, it is the higher-level participants that perform better than the lower-level participants in both the initial learning and retention of vocabulary.Based on the results of the two experiments, for teachers and text compilers, it’s important to take different learners’ proficiency levels into account. That is to say, the given tasks should neither be too difficult nor too easy, but in a difficulty level range that is challenging but achievable to learners of different proficiency levels, or the given tasks should be designed with various difficulty levels for learners of` different proficiency levels to choose their own suitable tasks. What’s more, the given tasks should have varieties that can fully initiate students’ motivation in vocabulary learning and improve their learning efficacy.