This study investigates the claim that task-induced involvement load has an effect on vocabulary learning and examines the effect of task types and word concreteness on intentional vocabulary learning in the Korean EFL context. This study aims at testing whether productive word-focused tasks lead to equally effective vocabulary learning when the total involvement load index is equal but the distribution of index levels of each component (need, search, and evaluation) is different. The three productive word-focused task types are gap-fillig, sentence writing, and gap-filling through word transformation. In addition, in order to investigate the effect of word concreteness on vocabulary learning, two groups of target words were selected based on the level of word concreteness. In sum, the results of this study generally supported involvement load hypothesis (Laufer & Hulstijin, 2001) and test types and proficiency levels proved to be important variables that affect vocabulary learning. Moreover, the findings also indicated that word concreteness was not a major factor in vocabulary learning. The pedagogical implications and further suggestions are discussed.

With an effort to verify the involvement load hypothesis, this study investigates the effects of three different vocabulary learning tasks - reading, filling in blanks, and sentence writing - on learners' short and long term memory when they are provided with the theoretically identical level of involvement tasks. It is also to examine whether there are any differences of learning effects between input and output vocabulary learning tasks. The experiments were conducted with 86 Korean middle school students grouped by three different task types. Pre-/post-tests and delayed tests were administered and analyzed. It was found that three vocabulary tasks with theoretically identical levels of involvement do not have the same learning effects: the involvement load hypothesis was not completely proved in the case of Korean students' vocabulary learning. The findings implied that (i) the difference of vocabulary learning tasks should be considered even though they have the same involvement load; (ii) given that EFL students learn new words in a limited amount of time in class, the reading task using a dictionary is found to be very helpful; and (iii) it is important to study target vocabulary repeatedly during class and to expose the vocabulary with different tasks to enhance students' retention of the newly learned vocabulary.