In this video, the teacher explains how to write a strong thesis statement using the acronym "BOS." They review the difference between opinions and statements that can be disputed, and discuss the importance of defending one's opinion. They then guide students through the process of developing a strong thesis statement by asking themselves three questions: Is it broad enough? Can I think of three reasons to support it? Is it an opinion or a statement? By following these steps, students can ensure that their thesis statements are clear and strong.