Research Method RESEARCH METHODOLOGY
it is very difficult to carefully define many of the numerous variables involved in language learning. Therefore, some factors such as subject selection,
instrumentation, and history, which may contribute to the internal validity of the study, are controlled.
Table 3.1 Research Design Factorial Data Analysis 2 x 2
Learning Motivation Instructional Media
Video A1 Picture A2
High Motivation B1 A1B1
A2B1 Low Motivation B2
A1B2 A2B2
Explanation: A1B1 = video learning with high motivation students
A2B2 = picture learning with high motivation students A1B2 = video learning with low motivation students
A2B2 = picture learning with low motivation students 1. Controlling the Extraneous Variables
Extraneous variables are factors other than the independent variable that might affect the dependent variable. The extraneous variables in this research
were related to internal and external validity. It was needed in experimental research to control the internal and external validity. Experimental researchers
need to identify potential threats of their experiments and design them so that these threats will not likely arise or are minimized. Creswell, 2009, p. 162.
a Internal Validity Internal validity is the extent to which extraneous variables have been
controlled. Internal validity asks, do the experimental manipulations make a difference? Campbell and Stanley as cited by Creswell, 2009, p.163
address eight types of extraneous variables which pose a threat to internal validity. In this research, the researcher only put some of extraneous
variables which can make a threat in this research.
- History History in here is events that occur between a pre and post-
measurement of the dependent variables. In controlling possible threats from the history, the researcher gave the equal length of taking the research
for the control group and the experimental group.
The researcher gave a pre-test on August 3, 2015 to both the control group and experimental group with listening comprehension test. After
that, from August 10 until October 7, 2015, both groups were taught with the same material about listening but using different media, the control
class was used picture and the experimental class was used video. The researcher gave the same starting points in the first meeting in which both
the control group and experimental group conducted the pre-test. Finally, the researcher used the last meeting to give the post-test for both groups
which was conducted at the same time on October 14, 2015. Based on the explanation above, the difference in the post-test scores between the two
groups was not due to the history events.
- Maturation Maturation is internal conditions of the participants that change as a
function of time. Participants in an experiment may mature or change during the experiment, thus influencing the results Creswell, 2009, p.
163. Maturation is controlled in that the researcher should be manifested equally in experimental and control groups.
Based on the explanation above, it is almost the same in controlling the maturation with controlling the history. In here, the researcher gave the
equal length of taking the research for the control group and the experimental group. The researcher gave the pre-test for the control group
and the experimental group at the same time which is on August 3, 2015. After that, both groups were taught at the same length of time which spent
10 meetings. The teaching and learning were started from August 10, 2015 until October 7, 2015. Finally, the researcher used the last meeting to give
the post-test for both groups which was conducted at the same time on October 14, 2015. Based on the explanation, it can conclude that the
participants in control group and experimental group matured at the same rate. Both the control group and experimental group were manifested
equally.
- Statistical Regression Statistical Regression is any change that can be attributed to the
tendency of extremely high or low scores to regress toward the mean. The researcher paid attention to construct the instrument to avoid the threat
from statistical regression. She developed the research instrument of listening in the form of multiple choices. This kind of test items was used
in the study to minimize the confounding of listening because it has no production requirements. The test is also fast and easy to score because no
judgment is required on the part of the scorers.
As the test items were used to make a confident claim about the effect of video
and picture on students’ listening comprehension, the reliability of the test were considered. The listening test that used in this
research was taken from TOEFL Junior Standard Test, the test used the most up-to-date methods for language testing and are fair, reliable and
valid for intended purposes. Because the listening test had met the validity and reliability, the researcher used this as the instrument to measure the
students’ achievement in listening comprehension test. By doing so, the internal validity from the statistical regression was well controlled.
- Instrumentation testing Instrumentation is changes that occur as a function of measuring the
dependent variable. Like maturation, the threat from testing was controlled in that it was manifested equally in control and experimental
group. It is possible that a pre-test may sensitize participants in unanticipated ways and their performance on the post-test may due to the
pre-test, not to the treatment. In controlling the threat from the instrumentation, the researcher conducted the pre-test to the control and
experimental group at the same time. She was done it to make sure that the different scores between the control and the experimental group were
because of different treatment, not because of the test.
- Selection Selection is changes due to using different criteria to place the
participant in the various comparison groups. A threat in non-equivalent control group design can caused from the selection of sample for the
control and experimental group. Based on this, the researcher chose two intact groups randomly from six classes in the eighth grade of SMPN 8
Tangerang Selatan to control the threat.
Therefore, making separate classes to do the experiment in a school is not allowed, so to make it easier the researcher use the classes that
already available in that school. The researcher chose two classes randomly from the eighth grade for being the control and experimental
group to avoid the matching as the main threat of selection. She got two classes; they were from class 8.4 and 8.5. Because the researcher also
taught in both of the classes, she believed that the participants will give
their best to learn the material and for the research. The participants didn’t know that they were the subjects of a research. Based on the way how the
researcher took the sample, it could be assured that the threat from selection could be controlled.
- Mortality The mortality is related to lost cases, and cases on which partial data
are available. Participant drop out during an experiment due to many possible reasons. The outcomes are thus unknown for these individuals
Creswell, 2009, p. 163. The researcher controlled the participants’
presence during the research to avoid the threat of mortality. It was also to make sure that there were no participants resigned during the research.
Because of the researcher also taught both classes in that school, so it was not so difficult for the researcher to monitor the participants of the
research. The researcher used
the attendance list to check the students’ presence during the teaching and learning activity, especially during the
time of the research. Based on the attendance list while the research conducted, there was no students’ who was absent during the 12 meetings
of this research, it could be assured that there was no lost cases.
b External Validity In this research, to control the external validity the researcher
conducted a random selection to choose the participants from the population. She was chose two classes randomly from the six classes then she got class 8.4
and 8.5.
After that, from the two sample classes, the researcher applied a test in which she chose randomly the two classes to determine the class for
experiment. Then, she got 8.5 as the experimental group. Therefore, both of the classes didn’t know that they were a subject of
a research that the researcher conducted in their class. They wouldn’t know because the researcher also taught in their class based on the schedule given
from the school.