page 88. Tryout test consisted of 12 difficulty items, 60 average items and 8 easy items. The easy and difficult items were dropped, while the satisfactory were
administered in pretest and posttest. For discrimination power, the were 10 bad items, 14 poor items, 37 good items, 17 satisfactory items and 2 excellent items.
Items with negative discrimination were dropped and revised, and the items that has satisfactory level of difficulty and good discrimination indexes were
administered for pretest and posttest.
3.8. Data Analysis
After conducting pretest and posttest, the researcher analyzed the data. In order to find out whether there is any significant increase of the students’ vocabulary
achievement. The researcher examined the students’ score using the following steps:
1. Scoring the pretest and posttest.
There were 30 items in the pretest and posttest, total correct items will be divided to 3 and times 10. So, the total score of the correct items was 100.
= 3
10
Where : TS : Total Score
CI : Correct Items 2.
Tabulating the result of the students’ score and calculating the mean of the pretest and the posttest.
3. Drawing conclusion from the tabulated result of the pretest and posttest
administered, that is by statistical computerization i.e. repeated measure T- Test of SPSS version 17.0.
3.9. Hypothesis Testing
The hypothesis testing is used to prove whether the hypothesis proposed in this research is accepted or rejected. The hypotheses of this research were:
1. There is significant increase of students’ vocabulary achievement of the
second grade of SMP Muhammadiyah 3 Bandar Lampung after being taught using STAD technique.
2. There is no significant increase of students’ vocabulary achievement of the
second grade of SMP Muhammadiyah 3 Bandar Lampung after being taught using STAD technique.
V. CONCLUSION AND SUGGESTION
This chapter is consisted of conclusions of the research’ result and also the suggestion from the researcher to the other researchers and to English teacher who
want to try to use STAD as a technique in teaching vocabulary.
5.1. Conclusions
After conducting the research in SMP Muhammadiyah 3 Bandar Lampung and analyzing the data, the researcher makes some conclusions as follow:
There was a significant increase in the students’ vocabulary achievement of noun parts of body, adjective describing object and verb activities after being
taught using STAD technique.
It was concluded that the use of STAD technique did affect positively on students’ vocabulary achievement. It is proven by the improvement on students’ score
between the pretest and the posttest.
