An Empirical Study Of The Effects Of Comprehensible Input On Second Language Vocabulary Acquisition

Vocabulary acquisition research is the essential part of the second language acquisition(SLA). Input is a vital link in the complex process of SLA. Although there are some controversies about whether the comprehensible input can directly facilitate the second language acquisition or not, the importance of comprehensible input on language comprehension, production and vocabulary acquisition cannot be denied. This thesis focuses on the effects of the comprehensible input on vocabulary acquisition.In order to identify the effects of the three types of comprehensible input—the simplified input, elaborated input and enhanced input—on L2 vocabulary recognition and production, we employ a pretest-posttest-delayed posttest design. We intend to solve the following questions:(1) whether the comprehensible input facilitates the L2 vocabulary recognition or not;(2) whether the comprehensible input facilitates the L2 vocabulary production or not;(3) what the acquired proportion of each word‘s class is.We chose 142 non-English major college students as subjects. They were randomly selected from six ordinary-level classes and were assigned into three experimental groups, which were also control groups to one another. In order to examine the effects of comprehensible input on vocabulary recognition and production, the participants were provided with different types of input. After this, the participants were given a posttest immediately for testing the vocabulary recognition, and then a delayed posttest was conducted to test their vocabulary production. We used SPSS(16.0) to collect and analyze the data of this study.The major findings in this study are as follows:(1) simplified and elaborated input can facilitate the L2 vocabulary recognition and production with a significant effect on long-term vocabulary recognition;(2) through affecting the internal recognition process, the simplified and enhanced input is helpful to the formation of connection of form-meaning of words;(3) the elaborated and enhanced input effectively facilitate vocabulary recognition especially on the short-term and long-term memory;(4) simplified and elaborated input, simplified and enhanced input and elaborated and enhanced input facilitate the vocabulary production, among which the elaborated and enhanced input outperformed;(5) different types of comprehensible input have different effects on L2 vocabulary acquisition, while the effects of comprehensible input on vocabulary acquisition mainly depend on the notice of the L2 learners to the target forms;(6) the results of the L2 learners‘ vocabulary recognition and production show that the recognized words in long-term memory are more than those in the short-term memory; produced words outnumber their recognized words; the most lexical forms L2 learners recognized was adjective, which was followed by phrases, verbs, and nouns;(7) there is a weak correlation between the vocabulary recognition frequency level and GET band level, and there is no significant difference.Finally, our study confirms the positive role of comprehensible input in L2 vocabulary acquisition and its practical significance in second language teaching. And we also enlist the limitations of our study. As for second language teaching, especially those vocabulary-oriented teaching activities, we suggest using the elaborated and enhanced input together to help the vocabulary acquisition in short-term as well as the long-term memory.