C. Population and Sample
The population of this research was the whole students of eleventh grade students of SMA Negeri 90 Jakarta. There are nine classes that consist of four social
science classesand four of science classes.Clustering sampling was used to take the sample. Houser stated that cluster sampling is used if the target population group
cannot be separated.
3
Based on cluster sampling technique, one class was taken randomly from nine classes that have same average score class. The class chosen was
XI Social 2 as the sample of this research. There are 40 students of that class.
D. Instrument of the Research
In this research, test was the instrument used in collecting the data. The test was used to find out if there is an effectiveness of using story mapping to teach students
writing ability of narrative text. Narrative is a text which is commonly used to tell an imaginary story or someone’s experience. The test was given in the beginning and in
the end of thetreatments. The test was in form of essay. The indicators of the testwere to build students’ understanding in narrative text, so that they were able to produce a
narrative text using their own words. The written test has to pass a validity and reliability test. Validity is when a test
must measures what it is intended to measure and what has been taught.
4
It means that students have to write in a genre that they have already learned. In order to be
valid, construct validity is used to create the test. As Hyland stated, Construct validity consists of the task which has qualities to measure how far writing abilities that have
been learned already by students.
5
It could be said that a test has construct validity if it measures cognitive aspects that has been elaborated in indicator that stated in the
curriculum. That is why before choosing theme, it should be compared to the indicators that students have to reach in syllabus. Then, it is shows that theme of
students’ writing of narrative text is valid.
3
Rick Houser, op. cit., p. 133.
4
Ken Hyland, Second Language Writing, New York: Cambridge University Press, 2003, p. 217.
5
Ibid., p. 218.
Moreover, reliability is also needed to create a good test because a test must be reliable as a measuring instrument.
6
In order to make the instrument to be reliable, the rubric of writing named “analytical scoring” which is created by Jacob, et al was
used. The advantage of this rubric scoring is that the scores are compiled to consider aspects of performance which they might otherwise ignore and the score has to give a
number of score will tend to make the scoring more reliable.
7
The composition profile by Jacob et al can be seen in research methodology.
E. Technique of Collecting Data
Test was used to see the result of students’ improvement in their writing ability of narrative text. The test was distributed to the experimental class. There were two
kinds of tests used: pre-test and post-test. a.
Pre-test Pre-test is conducted before the implementation of story mapping technique to
find out the average score of writing ability of the class which observed. Students were given a theme of story which is familiar with them. Students should write with
minimum 250 words. Then, students had to identify the element of narrative text such as orientation, complication, and resolution from the text which they had written. The
test was carried out in form of written test. b.
Post-test Post-test was used to find out if story mapping technique is effective to teach
students’ writing ability of narrative text. The post-test wasconducted after the implementation of story mapping technique teaching to see the improvementin that
the students made after the treatment given. The test used was same as the test used in the pre-test which consists of a narrative essaywith minimum 250 words to be written
by the students, but the theme which was given in pre-test and post-test was different.
6
J.B. Heaton, Writing English Language Test, London: Longman, 1995, p. 159.
7
Ibid., p. 162.