The selected respondent for this research was 8-1 class which consisted of 37 learners. Then, the respondents were given post- test to measure their achievement
after they were given a treatment, teaching comparative adjectives by using pictures.
Further, for gathering qualitative data, knowing learners’ perception of the use
of pictures in learning comparative adjectives, the researcher selected the respondents based on their gained score pre- test and post- test. The researcher
used clustering sampling in determining the respondents of qualitative data collection by grouping them based on the gained score. The researcher selected
this sampling because she intended to investigate learners’ perception of the use
of pictures in learning comparative adjectives from all level of gained score. The respondents might perceive the using pictures in learning comparative adjectives
positively or negatively. Six learners who selected came from three categories of gained score- high, medium, and low. It meant that from each category of gained
score, the researcher selected two learners to be respondents in gathering qualitative data.
D. Research Instrument
In this research, the researcher used two research instruments. Firstly, for gathering the quantitative data, the researcher used test as the research instrument.
Moreover, for gathering the qualitative data, the researcher interviewed the respondents.
1. Test
In collecting the quantitative data, the research instrument which was used in this research was a test which was developed by the researcher. The tests which
were used in this research were pre-test and post-test. Further, the material of the test was taken from learners hand book and other book about comparative
adjectives. The type of test was multiple- choice which consisted of 30 items from number
1 to number 30. The score per item was 10. It meant that if the respondents could
choose the answer of 1 item correctly, they would get 10 score. Further, to get a total score, the writer used formula as following:
Total score = amount of true items 3
From the description of each test from above, the highest score of this test was 100 scores.
Before the test was given to the respondents, the researcher did a pilot study in SMP YPPUI Ciledug Tangerang to measure a validity and reliability to know
whether the test is acceptable or not to use in this research. In conducting the pilot study to measure the validity and reliability of the test,
the researcher did some steps as following: a. the researcher made test specification with 9 indicators see Appendix 1
b. the researcher made 50 test items based on the test specification. c. the researcher gave the test to students of VIII-I of SMP YPPUI Ciledug
Tangerang which consisted of 40 students. d. the researcher scored the test and measured the validity and reliability of
the test by using data analysis in SPSS Statistical Product and Service Solution software.
After measuring the validity and reliability by using data analysis in SPSS, the reliability value of this test was 0,939.
5
Weir states that “A correlation of 0,9 or above is normally considered a desirable level of marker reliability...”.
6
Further, according to Lado on
Hughes’ book, Testing for Language Teachers Second Edition, the reliability coefficient of test is different based on types of language
tests. Lado states that “Good vocabulary, structure and reading tests are usually in
the .90 to .99 range”.
7
Hence, this test fulfilled the good reliability of vocabulary, structure and reading test.
5
Appendix 3, Validity and Reliability Test
6
Cyril J. Weir, Languange Testing and Validation, New York: Palgrave Macmillan, 2005, p.201
7
Arthur Hughes, Testing for Language Teachers Second Edition, Cambridge: Cambridge University Press, 2003, p. 39
