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P : percentage of students’ improvement
y : pre test result
y
1
: post test 1
P : percentage of students’ improvement
y : pre test result
y
2
: post test 2 The hypothesis in CAR is considered to be presented in a description of the
data gained during the research that is used charts, tables, etc. In order to support the acceptance hypothesis, the writer uses descriptive statistic, N-gain analysis
and students ’ response analysis.
1. Descriptive Statistic
Acording to Rusefendi in Statistika Dasar untuk Penelitian Pendidikan, descriptive statistic explains the quantitative data in the simple form.
26
In addition, the analysis of quantitative data refered in conversion data with the
rating scale five.
27
Interval Qualification
0.0 – 39.9
Too bad 40.0
– 54.9 bad
55.0 – 69.9
Medium 70.0
– 84.5 Good
85.0 - 100 Very good
2. N-Gain Analysis
In data analysis, the writer uses gain score to identify cognitive aspect or concept mastery of the students. Gain is the interval between posttest score and
26
Rusefendi, Statistika Dasar untuk Penelitian Pendidikan, Bandung: IKIP Bandung Press, 1998, cet. ke-1, p. 3.
27
Maifalinda Fatra and Abdul Rozak, Penelitian Tindakan Kelas, Jakarta: FITK UIN Jakarta,2010, cet. ke-1, p. 64-65.
47
pretest score. It shows the improvement score after the action. Meanwhile, to calculate students’ achievement in past continuous tense after implementing
CAR, the writer uses the formula as follow:
28
With the categories: g-high
: score g 0.70 g-middle : 0.70 g 0.3
g-low : score g 0.3
3. Analyzing Students Response
Besides analyzing the result of the tests and observing the activity during CAR, the writer also uses questionnaire to find out students’ response toward
using portfolio assessment technique in learning past continuous tense. The writer uses the Likert scale in scoring the answer of the question. In analyzing
the students’ response, the writer uses formula:
29
P = the percentage f = frequency of the percentage is being calculated
N = number of cases After tabulating all answers, the writer calculates the percentage of the
strength of the response by using formula as follow:
28
Siti Kartinah, Meningkatkan Hasil Belajar Biologi melalui Model Pembelajaran Portofolio pada Konsep Ekosistem, Skripsi UIN Syarif Hidayatullah Jakarta, Jakarta: Perpustakaan UIN
Syarif Hidayatullah Jakarta, 2008, p. 43. Unpublished Skripsi.
29
Anas Sudjiono, Pengantar Statistik Pendidikan, ..., p. 43
N-Gain = posttest score – pretest score
ideal score – pretest score
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After each answer is calculated, the score is processed based on the criterion of interpretation score as follow:
30
Percentage 0 - 25 = Very low
Percentage 26 - 50 = Low
Percentage 51 - 75 = Strong
Percentage 76 - 100 = Very strong
I. The Validity of the Study
Validity is an essential criterion for evaluating the quality and acceptable of the research regarding validity in action research, the writer adopt Anderson,
Herr and Nihlen’s criteria that mention the validity of action research including democratic validity, outcome validity, process validity, catalytic validity and
dialogic validity.
31
In this study, the writer uses democratic, process and dialogic validity. Anderson defines outcome validity as follows:
Outcome validity requires that the action emerging from a particular study leads to the successful resolution of the problem that was being
studied, that is, your study can be considered valid of you learn something that can be applied to the subsequent research cycle.
32
Based on the explanation above, the outcome validity could be seen from the result of the test. When the result of cycle two is better than cycle one, it
means that the study is successful. Then, process validity is “the validity that
requires study has been conducted in a “dependable” and “competent” manner.”
33
Next, the dialogic validity; “It involves having a critical conversation with
peers about research finding and practices.”
34
In this case, the writer and the teacher discuss and assess t
he students’ test result of cycle one and cycle two together. It is done in order to avoid invalid data.
30
Ridwan, Belajar Mudah Penelitian untuk Guru, Karyawan dan Pemula, Bandung: Alfabeta, 2005, p.89
31
Geoffrey E. Mills, Action Research: A Guide for the Teacher Researcher, ......, p. 84.
32
Geoffrey E. Mills, Action Research: A Guide for the Teacher Researcher, ......, p. 84.
33
Geoffrey E. Mills, Action Research: A Guide for the Teacher Researcher, ......, p. 84.
34
Geoffrey E. Mills, Action Research: A Guide for the Teacher Researcher, ......, p. 85.
49
J. Criteria of the Action Success
