| Enduring Understanding | Learning Objective | Essential Knowledge |
|---|---|---|
CLE-1 | 3.A |
|
Line of Reasoning and Methods of Development
AP English Language and Composition · Topic 3
3.1
Identifying Claims and Evidence
Syllabus
Source: College Board AP Course and Exam Description
Unit 3 is where the course stops being about parts and starts being about structure. Its subject is the line of reasoning 推理线索 - the path an argument takes from where it starts to what it proves.
First, four claims about how evidence gets into an argument properly:
- Effective use of evidence uses commentary 评述 to establish a logical relationship between the evidence and the claim.
- Writers introduce source material using commentary to integrate it into their line of reasoning - so commentary comes before as well as after.
- Synthesis 综合 requires consideration, explanation, and integration of others' arguments into one's own. That is the exact skill Question 1 tests, and the word integration rules out a paragraph that simply summarises each source in turn.
- Writers must acknowledge the words, ideas, images, and texts of others through attribution and citation 归属与引用.
| English | Chinese | Pinyin |
|---|---|---|
| line of reasoning | 推理线索 | tuī lǐ xiàn suǒ |
| commentary | 评述 | píng shù |
| Synthesis | 综合 | zōng hé |
| attribution and citation | 归属与引用 | guī shǔ yǔ yǐn yòng |
3.2
Developing a Paragraph with Claim and Evidence
Syllabus
| Enduring Understanding | Learning Objective | Essential Knowledge |
|---|---|---|
CLE-1 | 4.A |
|
Source: College Board AP Course and Exam Description
Applied to your own writing, the change from Unit 2 is that commentary now has two jobs, not one: it introduces the evidence into the reasoning, and it explains the relationship afterwards.
A paragraph that does both reads: claim - a sentence positioning the evidence - the evidence, embedded - commentary establishing the logical relationship - the link onward. The sentence before the quotation is doing as much work as the one after it, and most students write neither.
3.3
Describing the Line of Reasoning
Syllabus
| Enduring Understanding | Learning Objective | Essential Knowledge |
|---|---|---|
REO-1 | 5.A |
|
Source: College Board AP Course and Exam Description

The CED allows two arrangements, and both are valid:
- Writers may lead readers through a line of reasoning and then arrive at a thesis - the argument builds to its claim.
- Writers may express a claim and then develop a line of reasoning to justify it - the argument declares and then defends.
Whichever order is used, the same requirements hold:
- Writers explain their reasoning through commentary that connects chosen evidence to a claim.
- Commentary explains the significance and relevance of evidence in relation to the line of reasoning.
- The sequence of paragraphs in a text reveals the argument's line of reasoning - which is the practical tool for reading. To find a writer's reasoning, write one sentence per paragraph and read the list.
- Flaws in a line of reasoning may render an argument specious or illogical 似是而非.
| English | Chinese | Pinyin |
|---|---|---|
| Flaws in a line of reasoning may render an argument specious or illogical | 似是而非 | sì shì ér fēi |
3.4
Developing a Line of Reasoning and Commentary
Syllabus
| Enduring Understanding | Learning Objective | Essential Knowledge |
|---|---|---|
REO-1 | 6.A |
|
Source: College Board AP Course and Exam Description
For your own essays, the useful discipline is to decide the order of your claims before writing any of them. An essay whose paragraphs could be shuffled without loss has no line of reasoning - it has a list.
Test a draft by asking of each paragraph: why does this come after the one before it? If the only answer is "it is another thing I know about the topic", the structure is a list and the reasoning point is at risk.
3.5
Recognizing Methods of Development
Syllabus
| Enduring Understanding | Learning Objective | Essential Knowledge |
|---|---|---|
REO-1 | 5.C |
|
Source: College Board AP Course and Exam Description
Methods of development 展开方法 are common approaches writers use to develop and organise the reasoning of an argument. The CED's list: narration, cause-effect, comparison-contrast, definition, and description. This unit treats the first two.
- Developing through narration 叙述: writers offer details about real-life experiences and reflections on them. The reflection is what makes narration an argument rather than a story - an anecdote with no reflection has supplied no reasoning.
- Developing through cause-effect 因果: writers present a cause, then assert the effects or consequences of that cause - or begin from an effect and trace it back.
| English | Chinese | Pinyin |
|---|---|---|
| Methods of development | 展开方法 | zhǎn kāi fāng fǎ |
| narration | 叙述 | xù shù |
| cause-effect | 因果 | yīn guǒ |
3.6
Using Methods of Development
Syllabus
| Enduring Understanding | Learning Objective | Essential Knowledge |
|---|---|---|
REO-1 | 6.C |
|
Source: College Board AP Course and Exam Description
Choosing a method is a rhetorical decision, not a stylistic one. Narration works when the audience needs to feel the situation before they will accept a claim about it. Cause-effect works when the audience already accepts the facts but not the connection between them.
Worked example (a real AP exam task). On a Question 1 synthesis prompt, compare two paragraphs using the same two sources. The weak version: "Source A says X. Source C says Y. Both discuss the issue." That is summary in sequence - no claim, no integration, no reasoning. The strong version: "The strongest objection to the proposal is not that it fails but that it succeeds too narrowly: Source A's data show the intended outcome improving, while Source C's account of the same programme records the second-order costs that the measurement in Source A was never designed to capture." Here the sources are integrated into the writer's own claim, and the commentary establishes the logical relationship - which is what the four evidence-and-commentary points are awarded for.
3.6
Exam tips
- Commentary has two jobs: introducing evidence into the reasoning, and explaining the relationship afterwards. Write both sentences.
- Synthesis means integration, not summary in sequence. A paragraph per source is the classic low-scoring shape.
- To find a writer's line of reasoning, summarise each paragraph in one sentence and read the list.
- Ask of your own paragraphs: why does this one follow that one? No answer means no line of reasoning.
- Narration needs reflection. An anecdote without it has told a story, not made an argument.
- Choose a method of development for a rhetorical reason and be able to say what it is.
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