In this study, we analyzed the development of high school students’ argumentation through their writings on socio-scientific Issues (SSI) related to the Climate Change Unit in the Earth Science I curriculum. Pre- and post-writing assignments on the two main causes of global warming were analyzed and compared. In addition, an in-depth interview of the focus group was conducted with 7 students who showed a distinct change in the level of argumentation. According to the results, 16 of 52 students remained at the same argumentation level in pre- and post-writing assignments, and students remaining at Level 2 among five levels had difficulty in understanding the Toulmin’s argument pattern (TAP) structure. Using the TAP structure, 29 of 52 students demonstrated increased argumentation levels in the post-writing assignments. The conclusions include that writing lessons on SSI using the TAP in Earth science classes can improve the level of high school students’ argumentative writing, and that the level of students’ argumentation can develop with the elaboration of their level of falsification. Also, it is suggested that the science curriculum should increase students' science writing competencies by specifying science writing as one of the goals.

Abstract
Introduction
Methods
Results and Discussion
    1. Change of argumentation level: Developmental pattern of falsification
    2. Factors influencing students’ argumentation structure development
Conclusion
References

• Bhyung-ho Yoo(Jeonju YoungSaeng High School)
• Youngsun Kwak(Department of Earth Science Education, Korea National University of Education) Corresponding author
• Won-Mi Park(Department of Earth Science Education, Korea National University of Education)