The exhibition by students of scientific argumentation skill is an important part of the AP Physics 1 course. However, the development of this skill involves pedagogical expertise not commonly developed during teacher training. It's not surprising that student performance reports for AP Physics 1 consistently mention the lack of skill students exhibit regarding the justification of evidence used in supporting scientific claims. In this session, the findings of an action research study (a doctoral dissertation conducted by a veteran AP Physics teacher) will provide insights into whether time spent in developing scientific argumentation skill makes a difference in high-quality student argument creation. These insights may prompt AP Physics 1 teachers to incorporate specific pedagogical practices into their classes in order to better prepare students for the AP Physics 1 exam. Learning outcomes include improved teacher skills and improved student performance.