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Considering that the number of the population is great enough and since there is the limitation time, energy, and fund, not all the students of the second year become the
sample of this research. A sample is part of population, which was chosen to represent the population. For the efficiency and practically of the research, the second year students
are chosen randomly to represent the population. There are six classes altogether and four classes consist of 33 and two classes are 34 students and the total number of the second
year students is 200 students. So, the writer chooses 5 students from each class as the sample. It is presented by distributing or giving the paper to the students. The students
who get the paper with the word “sample” become the respondents. The population has the same chance to be the member of sample. They are not classified on the basis of their
grade of intelligence. Thus, there are 30 students as the respondents. The sample in this research is 15 . As Arikunto 2002:112 says, “If the population consists of a large
number, the sample can be taken from 10 - 15 or 20 - 25 or more, it depends on the ability of researcher by considering time, energy, and fund.
In obtaining the sample, the writer of this thesis used random sampling technique. Considering what Gay 1984:104 says that random sampling is the best single way to
obtain a representatives sample.
3.3. The Instrument of Collecting the Data
The instrument for collecting the data of this research is by distributing a questionnaire test in the form of objective test. Harris in his book “Testing English As A
Second Language’ 1969:132 defines: “Tests are often used to measure students’
progress in acquiring certain knowledge or skill by answering the question achievement
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test indicates the extent to which an individual has mastered the specific skill or body of information in formal learning situation”. By means of passive voice test the writer
collected the data. The writer taken the material of the passive voice test from the textbook of SMK Negeri 2 Pematangsiantar and from some exercises about passive voice
in simple past tense that had been taught by their English teacher. The questions test consists of 30 items. They did it in 60 minutes. The students are required to choose one
correct answer.
Blue Print of Instruments Types of Test
Number of Items
Number of each Items
Score of each Items
Passive voice in positive sentences as singular form
5 1, 2, 3, 4, 5
1
Passive voice in positive sentences as plural form
5 6, 7, 8, 9, 10
1
Passive voice in negative sentences as singular form
5 11, 12, 13, 14, 15
1
Passive voice in negative sentences as plural form
5 16, 17, 18, 19, 20
1
Passive voice in intterogative sentences with W-H questions
5 21. 22, 23, 24, 25
1
Passive Voice in intterogative sentences with yes-no
questions 5
26, 27, 28, 29 30 1
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3.4. Scoring the Test
In scoring the test given, the writer of this thesis determined the cummulative score from 0 – 100. To categorize the level of the students’ ability to master passive voice in
simple past tense, the following scale is used:
The Score of Ability Category
80-100 Very good
60-79 Good 40-59 Average
20-39 Poor 0-19 Very
poor Wayan and Sumartana, 1986:76
To know the students’ score in answering the test, the writer uses the following formula:
X =
100
N R
Where, X = individual score R = the number of correct answer
N = number of items The percentage of the classification of the students in answering question can be
calculated by using the following formula:
P =
100
r f
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Where, P = percentage f = number of frequency
r = total number of respondents Wayan and Sumantana, 1986
3.5. The Validity and the Reliability of Test
