The aim of this research was to find out the effectiveness of using graphic
organizer in students‟ reading comprehension for the eighth grade students of
SMP Muhammadiyah Sokaraja in academic year 2018/2019. The method of this
research was experimental research. The samples of this research were 22 students
from VIII A as the experimental group and 13 students from VIII B as control
group. The experimental group was taught using graphic organizer , while the
control group was conventional technique. Test was used to collect the data from
the experimental and control group. The test was divided into two sections,
namely pre-test and post-test. The pre-test was given for both of groups, before
giving the treatment, while post-test was given after giving the treatment. The pretest
and post-test consisted of 20 multiple choices. T-test formula was used to
analyzed the data. Based on the data analysis, it was found that t-test result score
was 3.59 while t-table score at the level of significance 0,05 for degree of freedom
33 was 1.692, so t-test was higher than t-table (3.59 > 1.692). It meant that
Graphic organizer was effective in students‟ reading comprehension of SMP
Muhammadiyah Sokaraja year 2018/2019. In conclusion, the hypothesis which
stated that the use of Graphic Organizer is effective for students‟ reading
comprehension was accepted.