Final answer:
The topical outline is used for organizing and firming up main points, allowing one to arrange subtopics in a logical or impactful order.
Step-by-step explanation:
The outline that is used for organizing and firming up main points is the topical outline. When using a topical pattern, you break your main ideas into smaller ideas or subcategories. This method requires you to think about the most logical or impactful order for your subtopics, which can vary based on your specific goals and the nature of the material.
For example, although some topics like historical events might seem well-suited to a chronological organization, in cases where the material doesn't have an inherent sequence, a topical organization allows you to arrange subtopics in a way that best supports your argument or narrative structure.