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Developing Strong Thesis Statements
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These OWL resources will help you develop and refine the arguments in your writing.
The thesis statement or main claim must be debatable
An argumentative or persuasive piece of writing must begin with a debatable thesis or claim. In other words, the thesis must be something that people could reasonably have differing opinions on. If your thesis is something that is generally agreed upon or accepted as fact then there is no reason to try to persuade people.
Example of a non-debatable thesis statement:
This thesis statement is not debatable. First, the word pollution implies that something is bad or negative in some way. Furthermore, all studies agree that pollution is a problem; they simply disagree on the impact it will have or the scope of the problem. No one could reasonably argue that pollution is unambiguously good.
Example of a debatable thesis statement:
This is an example of a debatable thesis because reasonable people could disagree with it. Some people might think that this is how we should spend the nation's money. Others might feel that we should be spending more money on education. Still others could argue that corporations, not the government, should be paying to limit pollution.
Another example of a debatable thesis statement:
In this example there is also room for disagreement between rational individuals. Some citizens might think focusing on recycling programs rather than private automobiles is the most effective strategy.
The thesis needs to be narrow
Although the scope of your paper might seem overwhelming at the start, generally the narrower the thesis the more effective your argument will be. Your thesis or claim must be supported by evidence. The broader your claim is, the more evidence you will need to convince readers that your position is right.
Example of a thesis that is too broad:
There are several reasons this statement is too broad to argue. First, what is included in the category "drugs"? Is the author talking about illegal drug use, recreational drug use (which might include alcohol and cigarettes), or all uses of medication in general? Second, in what ways are drugs detrimental? Is drug use causing deaths (and is the author equating deaths from overdoses and deaths from drug related violence)? Is drug use changing the moral climate or causing the economy to decline? Finally, what does the author mean by "society"? Is the author referring only to America or to the global population? Does the author make any distinction between the effects on children and adults? There are just too many questions that the claim leaves open. The author could not cover all of the topics listed above, yet the generality of the claim leaves all of these possibilities open to debate.
Example of a narrow or focused thesis:
In this example the topic of drugs has been narrowed down to illegal drugs and the detriment has been narrowed down to gang violence. This is a much more manageable topic.
We could narrow each debatable thesis from the previous examples in the following way:
Narrowed debatable thesis 1:
This thesis narrows the scope of the argument by specifying not just the amount of money used but also how the money could actually help to control pollution.
Narrowed debatable thesis 2:
This thesis narrows the scope of the argument by specifying not just what the focus of a national anti-pollution campaign should be but also why this is the appropriate focus.
Qualifiers such as " typically ," " generally ," " usually ," or " on average " also help to limit the scope of your claim by allowing for the almost inevitable exception to the rule.
Types of claims
Claims typically fall into one of four categories. Thinking about how you want to approach your topic, or, in other words, what type of claim you want to make, is one way to focus your thesis on one particular aspect of your broader topic.
Claims of fact or definition: These claims argue about what the definition of something is or whether something is a settled fact. Example:
Claims of cause and effect: These claims argue that one person, thing, or event caused another thing or event to occur. Example:
Claims about value: These are claims made of what something is worth, whether we value it or not, how we would rate or categorize something. Example:
Claims about solutions or policies: These are claims that argue for or against a certain solution or policy approach to a problem. Example:
Which type of claim is right for your argument? Which type of thesis or claim you use for your argument will depend on your position and knowledge of the topic, your audience, and the context of your paper. You might want to think about where you imagine your audience to be on this topic and pinpoint where you think the biggest difference in viewpoints might be. Even if you start with one type of claim you probably will be using several within the paper. Regardless of the type of claim you choose to utilize it is key to identify the controversy or debate you are addressing and to define your position early on in the paper.
Thesis and Purpose Statements
Use the guidelines below to learn the differences between thesis and purpose statements.
In the first stages of writing, thesis or purpose statements are usually rough or ill-formed and are useful primarily as planning tools.
A thesis statement or purpose statement will emerge as you think and write about a topic. The statement can be restricted or clarified and eventually worked into an introduction.
As you revise your paper, try to phrase your thesis or purpose statement in a precise way so that it matches the content and organization of your paper.
A thesis statement is a sentence that makes an assertion about a topic and predicts how the topic will be developed. It does not simply announce a topic: it says something about the topic.
Good: X has made a significant impact on the teenage population due to its . . . Bad: In this paper, I will discuss X.
A thesis statement makes a promise to the reader about the scope, purpose, and direction of the paper. It summarizes the conclusions that the writer has reached about the topic.
A thesis statement is generally located near the end of the introduction. Sometimes in a long paper, the thesis will be expressed in several sentences or an entire paragraph.
A thesis statement is focused and specific enough to be proven within the boundaries of the paper. Key words (nouns and verbs) should be specific, accurate, and indicative of the range of research, thrust of the argument or analysis, and the organization of supporting information.
A purpose statement announces the purpose, scope, and direction of the paper. It tells the reader what to expect in a paper and what the specific focus will be.
Common beginnings include:
“This paper examines . . .,” “The aim of this paper is to . . .,” and “The purpose of this essay is to . . .”
A purpose statement makes a promise to the reader about the development of the argument but does not preview the particular conclusions that the writer has drawn.
A purpose statement usually appears toward the end of the introduction. The purpose statement may be expressed in several sentences or even an entire paragraph.
A purpose statement is specific enough to satisfy the requirements of the assignment. Purpose statements are common in research papers in some academic disciplines, while in other disciplines they are considered too blunt or direct. If you are unsure about using a purpose statement, ask your instructor.
This paper will examine the ecological destruction of the Sahel preceding the drought and the causes of this disintegration of the land. The focus will be on the economic, political, and social relationships which brought about the environmental problems in the Sahel.
Sample purpose and thesis statements
The following example combines a purpose statement and a thesis statement (bold).
The goal of this paper is to examine the effects of Chile’s agrarian reform on the lives of rural peasants. The nature of the topic dictates the use of both a chronological and a comparative analysis of peasant lives at various points during the reform period. . . The Chilean reform example provides evidence that land distribution is an essential component of both the improvement of peasant conditions and the development of a democratic society. More extensive and enduring reforms would likely have allowed Chile the opportunity to further expand these horizons.
For more tips about writing thesis statements, take a look at our new handout on Developing a Thesis Statement.
Writing Process and Structure
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Getting Started with Your Paper
Interpreting Writing Assignments from Your Courses
Generating Ideas for Your Paper
Creating an Argument
Thesis vs. Purpose Statements
Developing a Thesis Statement
Architecture of Arguments
Working with Sources
Quoting and Paraphrasing Sources
Using Literary Quotations
Citing Sources in Your Paper
Drafting Your Paper
Developing Strategic Transitions
Revising Your Paper
Revising an Argumentative Paper
Revision Strategies for Longer Projects
Finishing Your Paper
Twelve Common Errors: An Editing Checklist
How to Proofread your Paper
Collaborative and Group Writing