The objective of this study was to determine the vocabulary size level and comprehensiveness about reading and listening on the senior high school students of SMA Budi Bakti. Vocabulary size level defined as the standard of the number of vocabularies needed for each person. This level was utilized by standardized test named Vocabulary Size Test (VST) developed by Paul Nation. Moreover, the last objective of this study was to describe the relation among these three variables.
The samples of this study was 72 students of tenth and eleventh graders in SMA Budi Bakti. The instruments used in this study were vocabulary size test, reading and listening comprehension test were taken from The Complete Guide to the TOEFL Test: PBT Edition by Bruce Rogers. The methods of collecting and analyzing the data were based on the guide to conduct research regarding vocabulary size by Nation (2012). Correspondingly, a prior research by Staehr (2013) was about the relation of vocabulary size and the skills of listening, reading and writing.
As the result of this study, it was discovered that the average score of the vocabulary size test taken by the subjects was 8207 word-families, which was considered as satisfying for non-native senior high school students. However, it was discovered from the data analysis taken from reading and listening comprehension test that was found to be strongly associated with their reading abilitiy and moderately associated with their listening ability.
However, vocabulary size could still explain a significant and substantial portion of the variance in the listening scores. These results thus emphasize the importance of vocabulary size for language proficiency. Furthermore, it was found that the majority of the learners did not know the most frequent 2000 words in English, but if they did, they would also perform adequately in the listening and reading tests. Eventually, the correlation was significant, thus, Ha was accepted and H0 was rejected.