A topic for your essay should emerge from your prewriting. Here are questions you can ask yourself to help move from topic to thesis:

• What assertion do I want to make about this topic?
• Does this assertion reflect my own thoughts and insights about this topic?
• Does this assertion offer one main idea?
• Is this assertion arguable? If not, how can I make it arguable?
• Is this assertion specific? If not, how can I specify?
• If the thesis is not working with what I intended to say, how can I revise it?
• Does the revised thesis have a topic and an angle?

Once you have a working thesis, analyze that working thesis carefully to make sure that it is a thesis, and that it has strong thesis characteristics.

The following video offers a writing instructor’s perspective about how fundamental a thesis statement is to organizing an effective persuasive, researched essay. While he talks about many aspects of a thesis, it particularly stresses the flexibility you’re allowed while writing, revising, and revisiting a thesis many times as you build an essay.

The Writing Center at The University of North Carolina Chapel Hill offers these questions to consider as you examine the effectiveness of a thesis statement. It’s effective strategy to revisit these questions several times throughout the writing process, to measure how well your thesis serves your project as it continues to grow and evolve.

• What is your general topic or what problem area are you interested in? How would you express it in a few words?
• What central question are you trying to answer about your topic?
• What do you think is the best answer to your central question? From your research so far, what have you concluded? What is your main point about your topic?
• In one sentence, how would you describe your findings to someone who asked you about your research?
• How does your idea differ from other views you have read? What do you have to say about your topic that is new? 
• Ask why? And how? of what seems like a thesis statement when it begins to emerge. What relationship exists between the ideas you are describing? For example, are you suggesting that one idea causes another? Contradicts another? Subsumes another?

Also view What Am I Trying to Say?: Creating Your Thesis