The rubric provides five aspects of writing namely content, organization, vocabulary, language use, and mechanic in which each of them
is scaled from 1 to 4. Hence the maximum score is 20, while the minimum score is 5. By knowing the highest score and the lowest score above, the
formulation of the ideal mean and the ideal standard deviation can be calculated as follows.
Maximum score = C + O + V + L + M
= 4 + 4 + 4 + 4 + 4 x 5 = 100 Minimum score
= C + O + V + L + M = 1 + 1 + 1 + 1+ 1 x 5 = 25
Ideal Mean=
excellent, very good, good, fair, poor, very poor. The table is presented as follows.
Table 4: The Conversion Table Class Interval
Interpretation
87.5 – 100 Excellent
75 – 87.4 Very good
62.5 – 74.9 Good
50 – 62.4 Fair
37.5 – 49.9 Poor
25 – 37.4 Very poor
Furthermore, there were two independent raters in assesing students’ writing. The first rater was the English teacher of Grade XII Science 1 who is
qualified for assessing students’ writing and the second rater was the researcher herself. In evaluating the students’ writing, she and the
collaborator gave an appropriate score in each aspect. The indicator of success could be seen from the increasing in the number of students who got
good scores in Cycle 2.
E. Data Collecting Instruments
In collecting the data, the researcher used several instruments. There were in the form of interview transcript, field notes, and students’ scores. The
interviews were conducted before, during and after the teaching and learning process with both English teacher and some students of XII Science 1 class. It
was aimed to get any information related to English teaching and learning process at SMA Negeri 2 Sleman especially in writing skill. It involved the
teacher and the students as well. The interview transcript could help the researcher planning the actions to solve the problems related to the writing
skill. The researcher also took a note during the English classroom in the form
of field notes. It covered students’ behaviours and motivation in learning English. The researcher and the collaborator were able to see and take a note of
students’ progress in the classroom. Field note was used to record anything happen in the classroom during the teaching and learning process and it could
be used by the researcher to determine the best actions. The last instrument was the rubric score of students’ writings. It was used
to assess the students’ writing ability in the pre – test and post – test. The rubric score focused on five aspects containing content, organization, vocabulary,
language use, and mechanic in those test. The range of writing score of each aspect was 1 to 4 consisting different indicator.
F. Data Analysis Technique
This research is qualitative in nature. However, the data were analyzed both qualitatively and quantitatively. The qualitative data were taken from the
field notes and the interview transcripts. The field notes stated everything that
happened in the teaching and learning process in the classroom. While the interview transcripts shows the students’ data that are related to their affection
in the process of teaching and learning writing. The researcher also analyzed the quantitative data to know the tendency
of students’ writing scores. In this case, she used mean and standard deviation in analyzing the quantitative data. MacKay 2006: 43 states that mean is the
average. In this case, it means the average of students’ writing scores. It was calculated by adding up all scores and dividing them by the number of
students in class. It is called empirical mean because it was gained by involving overall scores in the class. It should be above the ideal mean to
define that the group of participants has a good achievement. Ideal mean could be defined as the ideal mean score that has to be reached by the group. It is
calculated by adding up the highest score and the lowest score, and then dividing it into two.
In this research, the researcher also analyzed the students’ scores using standard deviation. Standard deviation is to identify whether a distribution is
heterogeneous or homogeneous Suharto, 2008: 16. It is called empirical standard deviation then. It should be below the ideal standard deviation to
show a positive result. If a distribution is homogeneous, it means that all students have the similar ability in writing using picture series. It is clear that,
if the scores are more tightly clustered around the mean, the standard deviation will be smaller, while, if they are spread out further from the mean,
the standard deviation will be larger.
G. Validity and Reliability of the Data
The validity and reliability of the data in this research was based on the criteria proposed by Anderson in Burns 1999: 161- 165. They are democratic
validity, outcome validity, process validity, dialogic validity, and catalytic validity. Each criteria is explained below.
a Democratic validity The democratic validity was obtained by interviewing the stakeholders
of SMA N 2 Sleman teachers, students, and school administrators. In the interview, the stakeholders were given chances to express their
ideas, opinion, and attitudes toward the problem faced, then the focus was to look for the solution of the problems. The interview was
conducted before, during, and after the actions to get their perspectives of the actions. She also had discussions with the English
teacher as the collaborator in reflecting the actions during the implementation of picture series.
b Outcome validity Outcome validity means that the research is “successful” in solving
the problems which are found in the writing class. The validity in this research was gained by analyzing the results of the actions. The results
of the research were not only able to solve the problems but also led to new questions. To get the outcome validity, the researcher put back
the problems at the Grade XII science 1 in a schema in order to make new questions.
