The thesis statement tells the reader what you are going to prove and how you are going to prove it. The reader should not have to spend time trying to figure out what your paper is about. The reader should feel confident that you have given her a road map to where she will end up when she is finished reading your work.
The thesis statement is a sentence (or two, or three) at the start of your paper (usually at the end of the introductory paragraph) that clearly states the main idea or point you will ultimately prove within the paper.
A thesis statement has 3 parts: the subject or topic you’ve chosen (which of course must meet the assignment requirements); a clear and precise opinion about the topic; and a clear set of reasons (usually three) why the opinion you set forth is the right one.
Let’s say your assignment is to write a paper answering the question “Are puppies adorable pets?” On its face, the assignment seems like a yes/no question. Yes, puppies are adorable pets, or no, they are not adorable pets. Done.
However, you are being asked to write a paper (that is, you are likely being asked to take a position) so you know you will have to write more than a sentence.
You decide that, yes, they are indeed adorable. This is the idea that you will prove to your reader.
An example of an ineffective thesis statement would be
“Puppies are adorable and everyone knows it.”
In your thesis statement, you state your position “they are adorable” AND you have to tell the reader why they are adorable. Unless you’ve taken a poll of “everyone” and have that data (an impossibility), you cannot prove the statement “everyone knows it.”
You collect some proof for your idea. You read about puppies, you have your friends and family fill out a short questionnaire, and you spend some time with puppies at the local pet shelter. Now you have a real sense of why puppies are so darn adorable. You will choose the 3 most compelling reasons list them in your thesis.
“Puppies are adorable because they are basically helpless, they are incredibly soft, and they do the funniest things.”
And there you go, that’s the thesis. Of course, you will have to have a sentence or two either before or after the thesis (or both) to cushion and finesse it (and because a paragraph is never only one sentence long.) It might go like this:
“Puppies have been known to melt the iciest temperament. They make us tear up when they cuddle with us, and they make us laugh with their antics. Even a skeptic would admit that puppies are adorable because they are basically helpless, they are incredibly fluffy and soft, and they do the funniest things.”
- SIDE NOTE: Most of the time you can’t really finalize your thesis until after you’ve done your research. You might think puppies are adorable but after reading about them, and maybe having a group of people fill out a questionnaire, and perhaps observing some puppies, you discover they’re actually the opposite of adorable: they are demons masquerading as live stuffed animals. So you’ll actually have to change your thesis entirely. This happens quite a bit to the best writers, and the best writers roll with the punches and follow the data.