in each score. It was used to know the students’ score as a whole on imperative sentence. It uses the formula:
5
: mean
x : individual score n : number of student
Second, the writer tries to get the class percentage which achieved the KKM 60 sixty. It uses the formula:
6
P : the class percentage F : total percentage score
N : number of students The third or the last, after getting mean of students’ score each cycle, the
writer identifies whether or not there might have students’ improvement score on imperative sentence from pre-test until posttest score in cycle 1 and cycle 2. To
analyze that, the writer uses the formula:
7
P : percentage of students’ improvement y : pre-test result
y1 : post-test
5
Sudjana, Metode Statistika, Bandung: PT.Trasito, 2002, p. 67.
6
Anas Sudijono, Pengantar Statistik Pendidikan, Jakarta: PT.Raja Grafindo Persada, 2008, p. 43.
7
David E. Meltzer, The Relationship between Mathematics Preparation and Conceptual Learning Gains in Physics: A possible Hidden Variable in Diagnostic Pretest score,
Iowa: Department of Physics and Astronomy, 2008, p. 3.
P = X 100
P : percentage of students’ improvement y : pre-test result
y2 : post-test 2
I. The Validity of Data
Validity is necessary in evaluating the quality of data that used in the research. By using the validity of data, the data or the instrument that used in the
research will acceptable. According to Anderson, et al in Mills’s book, criteria for validity in action research there are five kinds of validity. The criteria are
democratic validity, outcome validity, process validity, catalytic validity and dialogic validity.
8
In this research, the writer uses outcome, process, and dialogic validity.
Outcome validity is the validity that can be seen from the result of the test, with compared the result test of cycle 1 and cycle 2.
9
If the result of cycle 2 increased from the cycle 1, it means that the study is successful. Afterwards,
process validity is requiring the data has been conducted in a “dependable” and “competent” manner.
10
In the process validity, the writer observes all the activities that happened in the class during teaching learning activity. When finding some
problems, the writer and the teacher discussed to adjust the strategy for the next cycle. Furthermore, the dialogic validity “it involves having a critical conversation
with peers about research findings and practices.”
11
In this condition, to avoid the invalid data, the writer and the teacher discuss and assess the result of students’
score of cycle 1 and cycle 2. This is to measure whether the students’ score has improvement or not.
8
Geoffrey E. Mills, Action Research: A Guide for the Teacher Researcher, Ohio: Merrill Prentice Hall, 2003, p. 84.
9
Geoffrey E. Mills, Action Research: A Guide for the Teacher Researcher, … p. 84.
10
Geoffrey E. Mills, Action Research: A Guide for the Teacher Researcher, … p. 84.
11
Geoffrey E. Mills, Action Research: A Guide for the Teacher Researcher, … p. 85.
J. The Trustworthiness of Study
To analyze the validity of test items, the writer implements the trustworthiness of Study. The writer uses discriminating power and difficulty
item.
1. Discriminating power
The use of discriminating power of the test item is to know the performance of the test through distinguish students who have high and
low achievement into the high and low groups. The following is the formula to calculate the discriminating power.
12
D = N
L U
D = The Index of Discriminating Power.
U = The number of pupils in the upper group who answered the item correctly.
L = The number of pupils in the lower group who answered the item correctly.
N = Number of Pupils in each group. Then, the discriminating scale uses:
13
DP Remark
0.6 – 1.0 Very good
0.4 – 0.6 Good
0.1 – 0.3 Ok
-1 – 0.0 Bad
2. Difficulty Item
The difficulty item analysis concerns with the proportion of comparing students who answer correctly with all of students who follow
the test. Difficulty item is to know the difficulty of the test items.
12
Kathleen M. Bailey, Learning about Language Assessment: Dilemmas, Decisions, and Direction, London: Heinle and Heinle Publisher, 1998, p. 135.
13
J. B. Heaton, Classroom Testing, New York: Longman Inc, 1990, p. 174.
The following is the formula to calculate the difficulty item:
14
P = T
R P = Index of difficulty.
R = Total number of students who selected the correct answer. T = Total number of students including upper and lower group.
The following is the criterion of index difficulty:
15
ID Remark
0 – 0.30 High
0.30 – 0.79 Medium
0.80 – 1.00 Low
K. The Criterion of the Action Success
In the research, the writer needs to determine the criterion of the action success. The action can be called successful, if the action is able to surpass the
criteria that had been determined and fall if it is not able to surpass the criteria that had been determined.
16
Based on the statement above, the writer and the teacher discussed to determine the criteria of the action success. From the agreement
between teacher and the writer, the writer and the teacher agreed that this Classroom Action Research can be called success when there is 70 of students
could achieve the target score of minimal mastery level criterion-Kriteria Ketuntasan Minimal KKM 60 sixty of the imperative sentence test started
from the pre-test until the second post-test in cycle two.
17
If that condition has been reached, the writer did not necessarily have to carry out the next cycle.
14
Norman E. Gronlund, Construction Achievement Test, New York: Prentice Hall, 1982, p. 102.
15
Suharsimi Arikunto, Dasar-Dasar Evaluasi Pendidikan, Jakarta: Bumi Aksara,
2007, p. 210.
16
Sukidin, Manajemen Penelitian Tindakan Kelas, Jakarta: Insan Cendikia, 2007, p. 140.
17
Sarwiji Suwandi, Penelitian Tindakan Kelas PTK dan Penulisan Karya Ilmiah, Surakarta: Yuma Pustaka, 2010, p. 61
