Passage Structure and Evidence

Paragraph Function

Every paragraph in a well-constructed passage serves a Paragraph Function — introduction, support, transition, or conclusion. Identifying that function is the key to understanding how the passage is organized.

Introduction Paragraphs: Set the context, present the Thesis, and outline the scope. They often open with a broad claim or hook before narrowing to the specific argument. The last sentence of an introduction frequently contains the thesis.

Supporting Paragraphs: Develop one sub-point of the thesis. Each typically opens with a Topic Sentence followed by evidence, examples, or analysis. The topic sentence acts as a mini-thesis for that paragraph alone.

Concluding Paragraphs: Restate the thesis in fresh language, synthesize key points, and sometimes introduce a broader implication or call to action. They should not introduce entirely new arguments.

Transitional Paragraphs: Some passages include short paragraphs that serve as bridges between two major ideas, summarizing the preceding point and previewing the next.

Topic Sentence Identification

The Topic Sentence is the sentence that expresses the main idea of a single paragraph. It is usually — but not always — the first sentence, and every other sentence in the paragraph should relate back to it.

First-Sentence Rule: In roughly 70% of academic passages, the topic sentence is the first sentence. Start there, then verify by checking if the rest of the paragraph supports it.

Last-Sentence Topic Sentences: Some paragraphs lead with evidence or an example and build to a concluding insight. In these, the last sentence is the topic sentence.

Implied Topic Sentences: Occasionally no single sentence states the paragraph's point explicitly. In this case, you must infer it by asking what all the sentences in the paragraph have in common.

Supporting vs. Topic: A detail that illustrates or proves a claim is a supporting sentence, not the topic sentence. If removing a sentence doesn't change the paragraph's main point, it was a supporting sentence.

Types of Evidence

Authors support their claims using Evidence — facts, statistics, expert opinion, examples, and logical reasoning. Recognizing the type of evidence used helps you evaluate how strong the argument is.

Factual Evidence: Objective, verifiable data — dates, names, places, scientific measurements. This is the strongest form of evidence because it is independently checkable.

Statistical Evidence: Numerical data (percentages, ratios, counts). Watch for Qualifiers — 'nearly 50%' is not the same as 'half', and 'a threefold increase' is not the same as 'tripled to 300%'.

Expert Opinion / Authority: Citing a recognized expert or institution ('According to the WHO...'). This is persuasive but only as strong as the source's credibility — always consider whether the passage identifies the expert's credentials.

Anecdotal Evidence: A single story or personal experience. It is illustrative but not generalizable. A passage that relies heavily on anecdotes without broader data has a weaker argument.

Analogical Evidence: Comparing the unfamiliar to the familiar to build understanding. Useful for explanation but not proof — two things can be alike in some ways but different in the way that matters.

Evidence Strength Hierarchy

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Strongest: Peer-reviewed data from multiple sources

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Strong: Statistical studies with cited sample sizes

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Moderate: Expert opinion from a credible authority

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Moderate: Factual evidence (verifiable facts)

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Weaker: Anecdotal evidence (single stories)

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Weakest: Unattributed claims or appeals to emotion

Evidence-Claim Relationships

The relationship between Evidence and a claim determines whether the argument holds. Strong arguments pair each claim with directly relevant evidence; weak arguments use irrelevant, insufficient, or circular reasoning.

Direct Support: The evidence explicitly proves the claim. Example: 'Sales rose 40% after the campaign' directly supports 'The campaign was effective.'

Cumulative Support: Multiple pieces of evidence together support a claim that no single piece could prove alone. Each study alone is suggestive; together they are convincing.

Irrelevant Evidence: The evidence is true but does not connect to the claim. Example: Citing a company's revenue growth to prove employee satisfaction — the two may be unrelated.

Insufficient Evidence: The evidence points in the right direction but is too limited to support the claim's scope. Example: One small study supporting a broad universal claim.

Circular Reasoning: The evidence restates the claim using different words without providing independent support. Example: 'The policy is fair because it treats everyone equally' — 'fair' and 'equally' mean the same thing in this context.

Comparison and Contrast Structure

A Comparison and Contrast structure presents two or more subjects side by side, highlighting similarities and differences. This is one of the most common passage organizations in reading comprehension.

Block Structure (Subject-by-Subject): The passage discusses Subject A completely, then Subject B. All points about A appear before any points about B. This is common when subjects are very different and need separate context.

Point-by-Point Structure: The passage alternates between subjects for each criterion. First, both subjects on cost; then both on quality; then both on convenience. This is common when comparing on specific dimensions.

Mixed Structure: The passage may use block structure for background and point-by-point for the key comparison. Many real passages blend both approaches.

Signal Words: 'Similarly', 'likewise', 'in contrast', 'on the other hand', 'while', 'whereas', 'unlike', 'differing', 'compared to' — these words flag comparison and contrast.

Comparison Signal Words

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Similarity: similarly, likewise, in the same way, just as, equally, comparable

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Difference: in contrast, on the other hand, conversely, however, whereas, unlike, differing

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Both: both, alike, share, correspond, parallel, resemble

Cause-and-Effect Structure

A Cause-and-Effect structure explains why something happened (cause) and what resulted from it (effect). These passages require careful attention to Causation vs. Correlation — a distinction that authors sometimes exploit to strengthen weak arguments.

Direct Cause: A clearly identifiable event produces a specific result. Example: 'The dam burst, flooding the valley.' The burst is the direct cause of the flood.

Chain of Causes: Multiple linked causes where A leads to B, which leads to C. Example: Deforestation → soil erosion → reduced farmland → food shortages. Each link is both an effect and a cause.

Multiple Causes, One Effect: Several independent factors produce the same result. Example: Poor diet, lack of exercise, and genetics can each independently contribute to heart disease.

Correlation vs. Causation: Two things happening together does not mean one caused the other. Ice cream sales and drowning rates both rise in summer — they are correlated through temperature, but ice cream does not cause drowning.

Contributing Factor: A cause that is part of the picture but not the sole or primary cause. Recognizing this prevents over-stated conclusions.

Causal Signal Words

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Cause: because, since, due to, caused by, leads to, results in, brings about, is responsible for

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Effect: therefore, consequently, as a result, thus, hence, accordingly, so

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Correlation warning: associated with, linked to, correlated with, tends to

Argument Flow and Logical Organization

Understanding Argument Flow means tracing how an author builds a case — from the initial claim through supporting evidence to the final conclusion. A well-structured argument follows a logical progression that you can map as a chain of reasoning.

Claim → Evidence → Warrant: The classical argument structure. The Claim is the position. The Evidence is the data supporting it. The Warrant is the reasoning that connects the evidence to the claim — the 'because' that makes the evidence relevant.

Counterargument and Rebuttal: Strong arguments acknowledge opposing views (a Counterargument) and then explain why those views are wrong or less convincing (a Rebuttal). This strengthens the original argument by showing the author has considered alternatives.

Concession: Unlike a rebuttal, a Concession admits that the opposing side has a valid point without abandoning the main argument. Example: 'While it is true that solar panels are expensive upfront, the long-term savings outweigh the initial investment.'

Logical Ordering: Arguments can be organized by importance (strongest point last), chronology (events in time order), or problem-solution (state the problem, then propose solutions). The organization reveals the author's priorities.

Identifying Logical Fallacies in Structure

A Logical Fallacy is a flaw in reasoning that weakens an argument. Spotting these in passage structure helps you identify weaknesses in the author's case and anticipate the correct answer in critical reasoning questions.

Ad Hominem: Attacking the person instead of the argument. Example: 'Dr. Smith's research is wrong because she was paid by the industry.' This attacks credibility but does not address the research itself.

Straw Man: Misrepresenting the opponent's argument to make it easier to attack. If the opponent says 'We should reduce military spending by 5%', the straw man version is 'They want to abolish the military entirely.'

False Dilemma: Presenting only two options when more exist. Example: 'Either we cut taxes or the economy collapses.' This ignores the possibility of moderate approaches.

Hasty Generalization: Drawing a broad conclusion from limited evidence. Example: 'My two friends loved the movie, so everyone will love it.'

Appeal to Authority (Weak): Citing an authority outside their field of expertise. A famous actor's opinion on climate science is not authoritative evidence.

Quick-Fallacy Identifier

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Ad Hominem: '...but they can't be trusted because...' (attacks the person, not the idea)

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Straw Man: '...which means they want to...' (distorts the opponent's position)

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False Dilemma: '...either X or Y, there is no other choice' (ignores middle ground)

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Hasty Generalization: '...clearly this proves that...' (big claim, small sample)

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Appeal to Authority: '...according to irrelevant expert...' (wrong field or unnamed source)