This thesis discusses the effectiveness of song as a medium to improve vocabulary achievement for the seventh grade students of SMPN 16 Semarang in the academic year of 2011/2012. The statement of the problem in this study is how is the effectiveness of using song as a medium in teaching vocabulary for the seventh graders of SMPN 16 Semarang in the academic year of 2011/ 2012? The objective of this study is to find out the effectiveness of using song as a medium in teaching vocabulary for the seventh graders of SMPN 16 Semarang in the academic year of 2011/2012.
The population of this research was the seventh grade students of SMPN 16 Semarang. The research methodology was an experimental research which involved in two classes; the experimental class (VII A) and the control class (VII C). The VII A was taught by using song, while the VII C was taught without song (just conventional teaching). The writer gave objective vocabulary to gather the data. The test had been tried out to find out the validity, reliability, difficulty level, and discriminating power before it was used to gather the data. The formula that was used to analyze the data was t-test. It was used to determine whether there was a significant difference between students’ scores in the experimental class and in the control class or not. The writer used multiple choice test and documentation including syllabus, lesson plan of teaching and learning process, report of students’ development, teacher’s name list, and sketch of SMPN 16 Semarang in the academic year 2011/2012, as a method of data collection technique. The minimum of passing grade is 70 in SMPN 16 Semarang.
After the data had been collected using test, it was found that the pre-test average of the experimental group was 67.5 and control group was 68. 4. While, the post-test average of the experimental group was 86.80 and control group was 80.60. The obtained t-test was 4.095, whereas the t-table was 1. 66 for alpha ( ) 5%. The t-test score was higher than t-table (4.095 > 1.66). It meant that Ha was accepted while Ho was rejected. Since t-test score was higher than the t-table, song was an effective medium in improving students’ vocabulary at SMPN 16 Semarang in the academic year of 2011/ 2012. Finally the writer suggests to the teachers that they may use song as one of media in teaching vocabulary.