Evidence, Thesis, and Stylistic Choices

In 2014 the American Academy of Pediatrics, a body of children's doctors, said that middle and high schools should start at 8:30 a.m. or later, because teenagers' body clocks make them sleep later. In 2019 California made it law: from 2022 most public high schools could not start before 8:30. Doctors supported the change because of health. Some economists supported it because better-rested students learn more. Many parents and coaches worried about later sports practice, after-school jobs and bus timetables. Everyone was looking at the same clock, from a different place. A synthesis essay asks you to use voices like these, not just count them.

Unit 6 is the synthesis unit, and it contains the single sharpest distinction in the course.

• When synthesising 综合, writers draw on arguments from multiple sources 来源, strategically select the most relevant information, and integrate it into their own argument.
• A source provides information for an argument, and some sources are more reliable or credible 可信的 than others.
• A position 立场 and a perspective 视角 are different. Sources may hold the same position on a subject and yet each come from a different perspective.
• The strongest arguments recognise and acknowledge 承认 the other positions that exist.
• The degree to which a source considers other positions reflects the degree to which that source is credible - a test you can apply to any source on the exam.

The position-and-perspective distinction is what makes synthesis possible. If you sort the sources only by position, you get two piles - for and against - and a paragraph per pile. If you sort them by perspective, you can say things like:

Both the economist and the teacher support the measure, but they support it for reasons that do not survive together: one values the measurable gain, the other the change in what students attempt.

That sentence is synthesis. It uses two sources, is grounded in what each actually says, and produces a claim neither source makes.

Worked example: sorting four sources on school start times.

Sorting by position gives two piles. Sorting by perspective gives a claim: "A and B agree that a later start helps students, but D shows why schools still resist it: the cost is not in the classroom but in the bus timetable, so the real question is who pays for more buses, not whether sleep matters." That claim uses three sources, and none of them says it.

Also examinable: use the credibility test. A source that never acknowledges any other position is, by the CED's own standard, less credible - and saying so about a source is legitimate evidence in your essay.

A short but load-bearing point: consideration and use of new evidence may require revision 修改 of the thesis statement and/or changes to the line of reasoning.

Reading a text, this means a writer's thesis may be responsive - shaped by the evidence rather than imposed on it. Look for where an argument turns.

Writing under time pressure, this is permission you should use. If, while drafting, you find the evidence does not support the thesis you began with, change the thesis, not the evidence. Examiners reward an argument that fits its evidence; there are no marks for having predicted your own conclusion.

In practice, spend the first minutes reading sources and sketching claims before fixing the thesis. A thesis written after the evidence is nearly always better than one written before it.

• A writer's tone 语调 is the writer's attitude or feeling about a subject, conveyed through word choice and writing style.
• Readers infer 推断 tone from word choice - especially from the positive, negative, or otherwise charged 带感情色彩的 associations of the words chosen.
• A writer's shifts in tone 语调转变 from one part of a text to another may suggest qualification 限定, refinement 完善, or a change in perspective.

The third is the analytical gold. A tone shift is a visible event in a text: something changed at that point, and explaining what the writer wanted the reader to do differently after it is exactly the kind of answer that scores.

In your own writing, tone should be consistent and controlled, and deliberately shifted only where the argument turns - for example when moving from stating your position to conceding 让步 part of an opposing one.

Worked example (a real AP exam task). On a synthesis prompt, compare two uses of the same two sources. Weak: "Source B agrees with Source D that the policy should continue." That is position-sorting, and it produces nothing. Strong: "Sources B and D both defend the policy, but B defends it as an administrator measuring compliance while D defends it as a participant describing what it made possible - so the agreement is thinner than it appears, and the case rests on whether we are measuring the policy's operation or its effect." Same two sources, but the perspectives are doing the work, and the claim belongs to the writer.

Answer each before reading the model answers below.

1. Two sources both support a four-day school week: a head teacher writing about staff burnout 职业倦怠, and an economist writing about energy costs. Same position or same perspective? Explain.
2. Write one sentence that synthesises the two sources in question 1 into a claim neither makes alone.
3. A source on a new road never mentions any objection to it. What does the course's credibility test say about it?
4. Halfway through your essay you find that your best source contradicts your thesis. What should you do?
5. A passage moves from mocking a plan to "Yet the plan's defenders are not fools." What does this tone shift suggest?

1. Same position (for the four-day week) but different perspectives: one argues from teachers' wellbeing, the other from cost.
2. For example: "A four-day week appeals to schools for two unrelated reasons, staff wellbeing and energy savings, which suggests its support is broader than either group's interest."
3. A source that acknowledges no other position is less credible by the course's own standard, and you may say so in your essay.
4. Revise the thesis to fit the evidence, for example by qualifying it. There are no marks for keeping your first idea.
5. A shift toward qualification or concession: the writer is about to treat the opposing view more seriously, and wants the reader to judge the plan more fairly from this point.

• Position and perspective are different. This one distinction lifts most synthesis essays out of the middle band.
• Sort sources by perspective, not by side. Sorting by side produces a paragraph per pile and no argument.
• Use the CED's credibility test: a source that ignores all other positions is weaker, and you may say so.
• If the evidence does not fit the thesis, change the thesis. There are no marks for consistency with your first idea.
• A tone shift is a visible event. Say what changed and what the reader was meant to do after it.
• Keep your own tone controlled. Shift it only where the argument genuinely turns.

Vocabulary card meanings

shift in tone: A change in the writer's attitude partway through a text. position: The side a writer takes on an issue. perspective: The point of view or background a writer argues from.