5. Conducting the treatment
After giving pretest, the students were given three times treatment by using STAD technique based on the lesson plan which had been prepared.
6. Conducting the posttest
The posttest was administered after the application of STAD technique. The aim is to find out the students’ vocabulary achievement after the
implementation of STAD technique. 7.
Analyzing the test result After conducting pretest and posttest the researcher analyzed the data. The
data was computed through Statistical Package for Social Science SPSS version 17. The researcher then analyzed the students’ score from pretest and
posttest then make a discussion about the result. 8.
Reporting the result In reporting the data, the data was arranged systematically based on the
pretest and posttest to see whether there is an increase on the students’ vocabulary achievement.
3.6. Criteria of Good Test
In this research, to prove whether the test have a good quality or not, it has to be tried first. Try out is the test to measure the quality of the research instrument. The
test can be said had good quality if it has a good validity, reliability, level of difficulty and discrimination of power.
1. Validity
The test can be said valid if the test measures the object to be measured and it is suitable with the criteria Hatch and Farhady, 1982. To measure the test
has a good validity, this research used content and construct validity. Therefore, two types of validity will use in this research as follows:
a. Content Validity
Content validity is concerned with whether the test is sufficiently representative and comprehensive for the test. The researcher uses the
vocabulary that is supposed to be comprehended by grade VIII students. In this research, the researcher arranges the instrument based on the
material that will be given, which is vocabulary, specifically is content words noun, verb and adjective. If the instrument have represented all
the ideas that connected with the material that will be measured, that measuring instrument had fulfilled the aspect of content validity. Content
validity also can be examined from the table of specification that is presented below:
Table 3.1. Table of Specification of Tryout Test No.
Word Classes
Percent Number
Item Numbers
1 Noun
17,5 14
5, 7, 9, 17, 22, 28, 30, 42, 45, 49, 62, 68, 70, 78.
2 Verb
45 36
1, 3, 6, 10, 11, 13, 14, 16, 20, 24, 26, 27, 29, 32, 34, 35, 37,
39. 41, 43, 46, 50, 51, 53, 54, 56, 60, 64, 66, 67, 69, 72, 74,
75, 77, 79.
3 Adjective
37,5 30
2, 4, 8, 12, 15, 18, 19, 21, 23, 25, 31, 33, 36, 38, 40, 44, 47,
48, 49, 52, 55, 57, 58, 59, 61, 63, 65, 71, 73, 76, 80.
Total 100
80
