The Effects Of Different Input Modes On Incidental Vocabulary Acquisition

Vocabulary acquisition occupies a key position in the field of SLA. As one of the vocabulary learning methods, incidental vocabulary acquisition (IVA) has become a specifically popular subject. Many researchers have proved that IVA can occur through text or audio input, and the effectiveness of IVA under text-audio-video input has also been testified recently. However, few researches have been done to compare the effects of different input modes. For this reason, the author intends to investigate two central questions. Which input mode is most effective for L2 vocabulary acquisition and retention? Do students' different learning tasks have different effects on vocabulary acquisition and retention under different input modes?408 first-year non-English major students are randomly allocated to one of the eight treatments. The original scores of three vocabulary tests are taken and raw data are analyzed with SPSS 15.0. The results indicate that no matter what learning task it is, the text-audio-video input is most effective for vocabulary acquisition and retention, then follows text input, the audio input ranks at the third place, and text-audio input has the worst effect on vocabulary acquisition and retention; the rewriting task has better effect on vocabulary acquisition and retention than the comprehension task.Dual Coding Theory postulates the existence of two different storage systems for information—one for verbal codes and the other for nonverbal objects and events. Generative Theory of Multimedia Learning also supports the study. The two theories account for the best performance of text-audio-video input. The worst performance of text-audio input, however, is due to redundancy effect because of the identical textual and aural information. Text input has better effect than audio input due to different degrees of anxiety and different operating efficiency of working memory resulted from unparallel development of reading and listening ability. The rewriting task has better effect on vocabulary acquisition and retention than comprehension task, which verifies the effect of task-induced involvement load on IVA.