THE EFFECT OF APPLYING SEMANTIC MAPPING STRATEGY ON THE SENIOR HIGH SCHOOL STUDENTS VOCABULARY ACHIEVEMENT

This study was limited on the first year senior high school students vocabulary achievement after teaching by applying Semantic Mapping Strategy. The objective of the study was the investigation of the effect of applying Semantic Mapping Strategy on the senior high school students vocabulary achievement. The study was obtained by conducting experimental research that needed two groups of sample, experimental group and control group. The population of this study was the 2013/2014 first grade (grade X) students of SMA Negeri 2 Pematangsiantar. There were 70 students of first grade senior high school as the sample of the research. The experimental group was taught by applying Semantic Mapping Strategy, while control group was taught without applying Semantic Mapping Strategy. The instrument for collecting data was an objective test. The data were taken by administering the pre-test and post-test to both of experimental and control groups. Kudar Richardson (KR) 21 Formula was applied to acquire the reliability of the test. Based on the calculation, it shows that the reliability of the test was 0.71, categorized as substantial reliability. The data were statistically analyzed by using t-test formula at the level of significance p (0.05) = 1.995 with the degree of freedom (df) = 68. It was found that the tobserved was higher than ttable (tobserved= 3. 668 > ttable = 1.995; p = 0.05). It means that Semantic Mapping Strategy significantly affect the students vocabulary achievement.