Final answer:
Preliminary or tentative outlines are the early drafts of a speaker's main points that are subject to change during research.
Step-by-step explanation:
The early drafts of a speaker's main points that are subject to change during the course of research are called preliminary or tentative outlines. These outlines are a starting point for organizing ideas and can be revised and modified as the research progresses. They provide a roadmap for structuring the speech and can be used as a guide to ensure that all important points are covered.