This study suggests effectiveness of English teaching and learning utilizing
MMORPG in high school as teaching material. As teaching material, an
MMORPG, 'Goonzu Global', was selected and modified according to high
school English curriculum. Utilizing the game, English class, which consisted
of 30 students of first grade, was implemented by 20 lessons in a high
school located in Suwon. To achieve the goals of this study, the researcher
set four hypotheses according to effectiveness and retentive effects of the
class. Pre and post proficiency tests were conducted to verify effectiveness of
the MMORPG utilization in English class. Also, by comparing English scores
of two groups from regular mid-term test, which was taken one month after
the experiment, retentive effects were analyzed. At last, to find out affective
influences, survey and interview were carried out with the participants of the
class. As the results of the study, students' reading ability (hypothesis 1),
dialogue comprehension ability (hypothesis 2), and vocabulary recognition
(hypothesis 3) were all improved with statistical significance. However,
retentive effects (hypothesis 4) didn't show statistical significance although the
English mid-term test score of the experimental group was 5 point higher
than the comparative group.