6.2 Thesis and Supporting Evidence

The Core of an Essay: The Thesis Statement

Every effective piece of writing revolves around a central idea. In academic writing, this central idea is known as the thesis statement. The thesis is the anchor of your essay; it tells the reader exactly what to expect and sets the direction for the entire piece. On the PERT Writing exam, you will frequently be asked to identify the best thesis for a given passage or to recognize when a thesis is missing or flawed.

Characteristics of a Strong Thesis

A strong thesis statement is not merely a statement of fact or a vague observation. It must be a specific, arguable claim that requires defense or explanation.

Consider the differences between these statements:

• Weak (Statement of Fact): Many people use smartphones today. This is a fact. There is nothing to argue, and it doesn't give the essay a clear direction.
• Weak (Too Vague): Smartphones are bad for society. This is arguable, but "bad" is too vague. It doesn't explain how or why.
• Strong: Excessive smartphone use among teenagers decreases their attention spans and negatively impacts their academic performance. This is specific, arguable, and clearly outlines the points the essay will cover (attention spans and academic performance).

Thesis Placement

In standard academic essays, the thesis statement is typically placed at the end of the introductory paragraph. This placement allows the writer to introduce the general topic, provide necessary background context, and then narrow down to the specific argument right before transitioning into the body paragraphs. While reading passages on the PERT, look for the thesis in this structural location to understand the main purpose of the text.

Evaluating Supporting Evidence

Once a thesis is established, it must be supported. A thesis without evidence is merely an opinion. Supporting evidence comprises the facts, statistics, examples, expert quotes, and logical reasoning used to prove the thesis. Each body paragraph should focus on one specific point of evidence that connects directly back to the central claim.

Types of Evidence

Different topics require different types of evidence.

1. Factual/Statistical: Objective data (e.g., "According to the EPA, recycling rates increased by 10% last year.")
2. Anecdotal: Brief stories or personal experiences that illustrate a point. (Useful in descriptive or narrative essays, but less authoritative in research papers).
3. Expert Opinion: Quotes or paraphrases from recognized authorities in the field.
4. Logical: Rational deduction based on clear premises.

When evaluating evidence on the exam, ask yourself: Does this information prove the claim being made? Is the source credible? Is the evidence sufficient?

Relevance and Focus

One of the most frequently tested skills on the PERT Writing exam is the ability to identify relevant versus irrelevant information. Every sentence in a body paragraph must support the topic sentence of that paragraph, which in turn must support the thesis.

Irrelevant evidence is information that may be interesting or factually true but does not help prove the specific argument being made. Including irrelevant details distracts the reader and weakens the overall argument.

Example of Irrelevant Support

Imagine an essay with the following thesis: City parks are essential for community health because they provide spaces for exercise and foster social interaction.

Now, look at the following supporting sentences:

1. Parks with walking trails encourage residents to engage in daily cardiovascular exercise.
2. Community gardens within parks allow neighbors to meet and collaborate.
3. The city's first park was established in 1902 by Mayor Thomas Jenkins.
4. Open green spaces are utilized for weekend yoga classes, promoting physical wellness.

Sentence 3 is historically interesting, but it is entirely irrelevant to the thesis. It does not explain how parks provide spaces for exercise or foster social interaction. On the PERT, you will be asked to remove or replace sentences like this one to improve the essay's focus.

Strategies for Thesis and Evidence Questions

When tackling questions related to thesis statements and supporting evidence, keep these strategies in mind:

1. Identify the Main Idea First: Before evaluating a thesis or a piece of evidence, make sure you understand the overarching purpose of the passage. What is the author ultimately trying to say?
2. The "So What?" Test: If you read a sentence and find yourself asking "So what?" or "Why does this matter?", it is likely irrelevant or unsupported.
3. Check the Blueprint: A good thesis often acts as a blueprint for the essay. If the thesis mentions two main points, ensure the evidence provided addresses both of those points.
4. Eliminate Contradictions: Ensure that the supporting evidence does not contradict the thesis. Sometimes, a sentence might accidentally support the opposing viewpoint.

By learning to recognize a strong thesis and rigorously evaluating the relevance of supporting details, you will be well-equipped to analyze and improve written passages, a core competency evaluated on the PERT Writing exam.