A thesis is the main point or argument of an information source. (Many, but not all, writing assignments, require a thesis.)
A strong thesis is:
Research is usually vital to developing a strong thesis. Exploring sources can help you develop and refine your central point.
A strong thesis is specific and unique, so you first need knowledge of the general research topic. Background research will help you narrow your research focus and contextualize your argument in relation to other research.
Ask questions as you review sources:
Before committing yourself to a single viewpoint, formulate a specific question to explore. Consider different perspectives on the issue, and find sources that represent these varying views. Reflect on strengths and weaknesses in the sources' arguments. Consider sources that challenge these viewpoints.
Example: What role does and should the U.S. government play in regulating carbon emissions?
Is the topic:
Your thesis will probably evolve as you gather sources and ideas. If your research focus changes, you may need to re-evaluate your search strategy and to conduct additional research. This is usually a good sign of the careful thought you are putting into your work!
Example: Because climate change, which is exacerbated by high carbon emissions, adversely affects almost all citizens, the U.S. government has the responsibility to help reduce carbon emissions through public policy and regulation.