Introductions, Conclusions, and Development

Unit 4 covers the two positions in a text where a writer's choices are most visible - the beginning and the end - and completes the CED's list of methods of development.

• The introduction 引言 of an argument introduces the subject and/or the writer to the audience. It may orient the reader, establish the exigence and context, and gain attention.
• The conclusion 结论 brings the argument to a unified end. It may present the argument's thesis, explain its significance, or situate the argument in a broader context.

Note the verb in the second: unified. A conclusion is not a summary; it is the point at which the parts are shown to have been one argument.

On the exam, both are worth writing well but neither is worth writing long. A useful discipline:

• An introduction that positions the subject and states a defensible thesis in two or three sentences is complete. Everything else in a timed essay is better spent on evidence and commentary.
• A conclusion that says what follows from the argument - its significance, or its wider implication - does more than one that restates the paragraphs.

The weakest conclusion is the one that re-lists what the essay already said. The reader has just read it. Say instead what it means, or what it obliges.

The CED adds a precise refinement here: a thesis statement may preview the line of reasoning of an argument - and then, immediately, this is not to say that a thesis statement must list the reasons.

That double statement is worth holding, because both errors are common. A thesis that previews nothing leaves the essay shapeless. A thesis mechanically listing three reasons is not required and often produces a rigid essay that cannot develop.

For your own writing, the practical version:

• The thesis must be defensible. Non-negotiable, and it is the whole of the thesis point.
• It may indicate the shape of the reasoning. Do it when the shape is genuinely load-bearing; do not do it as a formula.
• It should be specific enough to constrain what follows. A thesis so broad that any paragraph could belong under it is not directing the essay.

Unit 3 covered narration and cause-effect. Unit 4 adds the rest:

• Developing through comparison-contrast 比较对照: writers present a category of comparison and then examine similarities and differences within it. The category is the part students omit - a comparison without a stated basis is two descriptions side by side.
• Developing through definition or description 定义与描写: writers relate the characteristics, features, or sensory details 特征与感官细节 of a subject.

Definition is more powerful than it looks. An argument that turns on what a word means - what counts as success, as fairness, as progress - is an argument that has moved to the ground where it can actually be won.

The choice is rhetorical. Ask what the audience needs before they will accept your claim:

• They need to see it, and abstraction is the obstacle: description.
• They accept the facts but not the connection: cause-effect.
• They are applying the wrong standard: definition.
• They will judge better against something familiar: comparison-contrast.
• They need to feel the situation: narration.

Worked example (a real AP exam task). A Question 3 argument prompt asks you to take a position on whether a common practice is beneficial. A student who reaches for description writes a vivid paragraph nobody disputes. A student who reaches for definition writes: "Whether the practice is beneficial depends on what we count as benefit. If benefit means measurable short-term gain, the practice succeeds; if it means durable capability, the same evidence shows it failing." That paragraph has relocated the argument onto ground where the evidence actually decides something - which is the kind of move the sophistication point exists to reward.

• Introductions should be short and load-bearing: position the subject, state a defensible thesis, move on.
• A conclusion that restates earns least. Say what the argument means or obliges.
• A thesis may preview the reasoning; it is not required to list reasons. Both errors are common.
• Comparison needs a stated category. Without one you have written two descriptions, not a comparison.
• Definition is the strongest move available in an argument essay whose terms are contestable.
• Pick a method of development from what the audience needs, not from what the topic suggests.