I quite
liked the answer on this topic posted on the UNC Chapel Hill
Writing Center website:
http://www.unc.edu/depts/wcweb/handouts/thesis.html
An interesting
website will attempt to automatically create a thesis statement
for you based on your answers to several questions.
http://www.ozline.com/electraguide/thesis.html
However, just in case those websites change or vanish, I will try to provide a brief answer here as well.
A thesis statement is a one sentence sum-up of your entire paper.
I sometimes consider the scientific process when it comes to a thesis statement. In a scientific experiment, your hypothesis (I believe this bottle will explode if I shake it) is a thesis statement. Your experiment will then prove or disprove that hypothesis. (Boom!)
In a paper, you will always be trying to prove your thesis statement is correct.
That means, however, that your thesis statement should not be completely obvious and general, such as,
Example that is NOT A thesis statement: To Kill a Mockingbird is a book.
A little too easy to prove, everyone knows it, etc. On the other hand, don't make your thesis statement too hard.
Another example that is NOT a thesis statement: To Kill a Mockingbird is the most influential book in this milennium.
Here are a few sample thesis statements....
The first two samples are thesis statements following a rather traditional approach in which you not only state your main point, but you also mention your main arguments in support of it.
Sample 1: Cold Mountain is an excellent medium for teaching North Carolina history, because it conveys the personal experience of life during the war, reveals the changes in people and society, and paints a moving picture of a lost way of life.
Sample 2: By using a child narrator in To Kill a Mockingbird, Lee is able to critique social mores and expectations, including parodying educational trends, questioning gender roles, and most of all, showcasing the tragedy of institutionalized racism.
The next two samples only state the main point and suggest the main points of discussion in the paper, but do not state the main arguments, but they may work as well. It sometimes depends on your professor.
Sample 3: A comparison of Chu's Eat a Bowl of Tea and Okada's No-No Boy reveals insights into the internal and external conflicts faced by Asian Americans following World War II.
Sample 4: Harriet Jacobs' Incidents in the Life of a Slave Girl supports the Social Historian theory on slavery.
My samples thus far have been based on a typical English essay (or in one case, a history paper that was focused on one book).
For the thesis of a research paper, you will want your thesis to sum up what you have learned (or found most interesting) from your research.
In my sample research paper on Mark Twain, here is my thesis statement:
Throughout his life, he faced many obstacles and failures, yet he was able to overcome, for the most part, each one. Mark Twains life encompasses all five steps of the POWER process.
(It is actually two sentences, which can be okay, though I usually recommend aiming for one sentence, and personally, I think it should always be the last sentence of your first paragraph.)
A few other possible thesis statements, depending on what I wanted to discuss in the paper. This statement was developed to answer directly the assignment (as should yours). But here are some other possible thesis statements for papers I could have written from my research on Mark Twain.
An analysis of several biographies of Mark Twain reveals a man with a shifting sense of identity which greatly shaped him as a writer and as an individual.
Mark Twain's life story demonstrates that a good writer must revise frequently, draw from his own weaknesses for ideas, and keep working regardless of personal setbacks.
The political views expressed by Mark Twain changed frequently to fit the audience he was addressing and his personal circumstances at the time.