"Source A says the city has only four sidewalk plows. Source C says a columnist who uses a wheelchair did not leave her block for nine days." Each sentence is accurate and cited, and together they argue nothing, because the writer has handed the paragraph to the sources and stepped out of it. A synthesis essay is scored on what you do with the sources: the claim they serve, the link you draw between them and that claim, and how you make them answer one another.
Commentary that names the link
Topic 1.4 covered writing a claim, embedding a quotation, and the basics of explanation, where commentary meant explaining why your evidence supports your claim. In Unit 3 you can make that explanation sharper by knowing which link you're asserting. Topic 3.3 listed the common ones: example to pattern, sign to conclusion, cause to effect, comparison, and principle applied. Each one makes a specific promise to the reader, and each one has a specific weak spot. Strong commentary names the link and protects its weak spot.
- An example stands for a pattern only if it's typical. Commentary says why this case is like the others ("the same thing happened on all three teams in our league that tried it").
- A sign points to a conclusion only if rival explanations are ruled out. Commentary says why this explanation fits better ("the drop came in the same month the fee started, and nothing else changed that month").
- A cause produces an effect only through a mechanism. Commentary spells the mechanism out step by step, so the reader can see each link hold.
- A comparison works only if the cases share the feature that matters. Commentary names that feature.
- A principle decides a case only if the reader accepts the principle. Commentary states it in terms this audience already holds.
You don't need every sentence of commentary to do all of this. But a paragraph that names its link and answers the first question a skeptic would ask is far harder to dismiss than one that says "this shows" and moves on.
Bringing a source into your line of reasoning
Topic 1.4 covered the mechanics of embedding a quotation and why a dropped quotation fails. The bigger decision is the role a source plays in your argument, because that decides how you frame it. Topic 3.3 named four roles: authority, opponent, concession, and raw material. When you write, choose the role first and build the frame to fit.
- Authority. Before the source, say why its word counts on this point. After it, say what it proves for your claim.
- Opponent. State the source's position fairly, then answer it with a reason, not a sneer. A fair summary of the other side is what makes your answer persuasive.
- Concession. Grant the point outright, then show why it doesn't decide the question or why your claim survives it.
- Raw material. Use the source's data, and draw a different conclusion from it than the source did. Say so openly ("The report treats this as a staffing problem; its own numbers suggest a scheduling one").
Whatever the role, the order inside your paragraph matters: your claim comes first and the source serves it. A paragraph that opens with a quotation lets the source set the agenda, and the reader can't tell what you think until much later, if ever.
Synthesis: making sources talk to each other
The synthesis essay gives you six sources on an issue and asks you to argue your own position using at least three of them. Synthesis means more than using several sources: it means considering what each one argues, explaining it accurately, and combining it with the others in service of your claim. The essay's structure follows from that.
- Organize by idea, not by source. Each body paragraph makes one claim that supports your thesis and draws on whichever sources bear on it. A paragraph per source ("Source A argues... Source B argues...") is a summary of the packet, and it can't earn the higher evidence-and-commentary scores, however accurate it is.
- Put two sources in the same sentence when they meet. "The city clears its 45 miles of priority routes within two days (Source A), which explains why Ferris's street was plowed by the second morning while her sidewalk was not, and why she did not leave her block for nine days (Source C)." The sources now explain each other, and the sentence says something neither source said alone.
- Use the sources that cut against you. A source that complicates your position is useful: concede what it gets right and show how your claim accounts for it. Explaining a tension like that is one way essays earn the sophistication point.
- Read the visual sources as evidence too. A chart or table needs the same commentary as a quotation: say which number matters and what it shows for your claim. "Source E shows that complaints rose" is description; "complaints rose 40 percent in the two winters after the ordinance passed (Source E), which suggests the fines didn't change behavior" is commentary.
Attribution in your own writing
Every time you use a source's words, ideas, or data, say whose they are. On the synthesis essay, cite in parentheses by the source's letter or by the short description the prompt gives it: "(Source C)" or "(Ferris)." That applies to paraphrase and summary as much as to quotation, and to numbers from a chart as much as to sentences: if the idea came from the packet, it gets a citation. In the argument essay, your evidence comes from what you know, and you don't need formal citations, but you should still say where a specific fact comes from when it matters to its credibility ("the town's own budget, posted on its website").
Attribution also helps your argument. It shows the reader which claims rest on a source and which are your own reasoning, so your commentary stands out as yours. And it lets you use a source's credibility, or its bias, as part of the argument, which you can't do with an idea you haven't credited.
Worked examples
A student is writing an argument essay on whether teams and clubs should rotate leadership roles instead of keeping one captain all season. Here is her draft paragraph:
Rotating captains gives quiet players a chance to lead. This fall my soccer team rotated the captain's armband every game. Two players who had barely spoken in practice ended up running warm-ups by October. This shows that rotating captains is a good idea.
Revise the paragraph so its commentary names the link and answers a skeptic.
Show solution
What's wrong. The claim and the evidence are fine. The last sentence is the problem: "This shows that rotating captains is a good idea" could be written without the evidence, and it skips the question every reader will ask, which is whether one team's season proves anything. The link is example to pattern, and an example only supports a pattern if the reader believes it's typical, or can see why it would happen elsewhere.
A revision.
Rotating captains gives quiet players a chance to lead, because it hands them the role before they would ever ask for it. This fall my soccer team rotated the captain's armband every game, and two players who had barely spoken in practice were running warm-ups by October. Neither changed personality in a month. What changed was that each of them had to stand in front of the team once, discovered the others would listen, and kept doing it. A permanent captain is usually chosen for confidence players already show, so a team that names one in August never finds out who could have led. One team is a small sample, but the cause it shows has nothing to do with soccer: any group that waits for volunteers will hear only from the people who already volunteer.
Why it works. The first sentence now states the mechanism ("hands them the role before they would ever ask"), so the example has something to illustrate. The commentary turns the example into a cause (being made to lead once, then being listened to), contrasts it with how permanent captains are picked, and then meets the skeptic directly: it admits the sample is small and argues that the cause applies to any group. That last move is what turns one anecdote into support for a general claim.
A synthesis prompt asks students to take a position on whether cities should require residents to clear the public sidewalks in front of their homes after snowstorms. Here are three of the sources (written for this lesson; their authors and data are invented).
Source A (Lindqvist, city public works memo): The city maintains 412 miles of sidewalk and owns four sidewalk plows. After a storm of six inches or more, crews clear the routes around schools and hospitals first, about 45 miles, which takes roughly two days. The remaining sidewalks are on no schedule.
Source C (Ruth Ferris, newspaper column): After the February storm I did not leave my block for nine days. My street was plowed by the second morning. The sidewalks were not, and my wheelchair cannot climb the three-foot ridge a street plow leaves at the curb.
Source D (Helen Amato, letter to the editor): I am seventy-eight and have a bad hip. Under the proposed ordinance I would be fined fifty dollars for every day I cannot do what my body will not let me do. I would gladly pay a neighbor's kid, if one were available at six in the morning.
The student's thesis: cities should require residents to clear their sidewalks, but only if the city clears them for residents who physically can't. Write a body paragraph that synthesizes the sources.
A weak version, for comparison:
Source A says the city has 412 miles of sidewalk and only four plows. Source C talks about a columnist in a wheelchair who could not leave her block for nine days. Source D is from a seventy-eight-year-old who cannot shovel. All of these show that snow is a big problem for cities.
Show solution
A model paragraph.
Leaving sidewalks to the city means leaving most of them uncleared, and the people that hurts most are the ones least able to wait. With four plows for 412 miles of sidewalk, the city reaches only about 45 miles of priority routes, and the rest are "on no schedule" (Source A). That schedule explains Ferris's nine days stuck on her block: the street outside was plowed by the second morning, but the sidewalk never came up in the city's rotation, and the street plow added a three-foot ridge at the curb that her wheelchair cannot climb (Source C). A requirement that each household clear its own frontage would spread the work across thousands of shovels instead of four plows. But a requirement alone would punish residents like Amato, who would owe fifty dollars a day for a limit set by her hip, not her will (Source D). Her letter shows where a fair ordinance has to start: the city should pair the requirement with crews or paid volunteers who clear the frontage of residents who apply for an exemption. Otherwise a law meant to let people like Ferris leave their blocks would fine people like Amato for staying home.
Why it works.
- It opens with the writer's claim, not a source, and each source then serves that claim.
- Sources A and C meet in one sentence: A's schedule explains C's nine days. That is the synthesis move: the sentence says something neither source says alone.
- The commentary names its link. "Spread the work across thousands of shovels instead of four plows" is a cause-effect argument for the requirement, built from Source A's numbers.
- Source D cuts against a simple requirement, and the paragraph uses it instead of ignoring it: it concedes the hardship and turns it into the qualification in the thesis. That is what the thesis's "but only if" was for.
- Every quotation, paraphrase, and number is cited, including the figures from A and the paraphrase of D.
The weak version cites the same sources and fails on every count: it is organized by source, it has no claim until a vague last sentence, it says nothing about how the sources relate, and "snow is a big problem" could have been written without reading them.
The passage below is a draft.
(1) Most students graduate from our high school without knowing how to fix anything in a house. (2) A dripping faucet, a running toilet, and a tripped circuit breaker are not engineering problems; each takes about ten minutes and a few dollars to fix once you know how. (3) Without that knowledge, students will pay a professional, or simply live with the problem. (4) Our school should offer a one-semester elective in basic home repair.
(5) The course would pay for itself in students' first apartments. (6) The town's two plumbing companies charge a minimum service fee of ninety dollars, before any work is done. (7) A course that teaches students to replace a faucet washer would save each of them that fee the first time a faucet drips. (8) Several teachers have said they would be willing to help.
(9) The skills would also make students more confident. (10) Mr. Lowell, who teaches the building trades class at the career center, said, "Kids who fix one thing stop being afraid of the next thing." (11) Students who have already taken his class describe the same change.
Question 1. The writer wants to add evidence after sentence 8 that would most strengthen the claim in sentence 5. Which of the following sentences best accomplishes this goal?
- (A) Home repair was once a common subject in high schools across the country.
- (B) The career center already owns the sinks, toilets, and wiring boards a course would need, so the school's only cost would be a teacher's time for one class period.
- (C) Many students enjoy working with their hands.
- (D) Some home repairs, such as rewiring a house, should be left to licensed electricians.
Question 2. The writer is considering revising sentence 10 (reproduced below) to better integrate the quotation into the paragraph's line of reasoning.
Mr. Lowell, who teaches the building trades class at the career center, said, "Kids who fix one thing stop being afraid of the next thing."
Which of the following versions best accomplishes this goal?
- (A) (as it is now)
- (B) "Kids who fix one thing stop being afraid of the next thing," Mr. Lowell said.
- (C) Mr. Lowell, who has taught building trades at the career center for twelve years, has watched this happen: in his words, "Kids who fix one thing stop being afraid of the next thing," because each repair proves that the problem in front of them can be solved.
- (D) According to a teacher, kids who fix one thing stop being afraid of the next thing.
Question 3. The writer wants to add a sentence after sentence 7 that explains how the evidence in sentences 6 and 7 supports the claim in sentence 5. Which of the following sentences best accomplishes this goal?
- (A) Ninety dollars is a lot of money.
- (B) Plumbers deserve to be paid for their skills.
- (C) Because one avoided service call saves more than a student would ever spend on washers and wrenches, the savings begin with the first drip and grow every year a student rents or owns a home.
- (D) Faucet washers are sold at most hardware stores.
Show solution
1. (B). Sentence 5 claims the course "would pay for itself," which is a claim about cost and benefit, and the paragraph so far shows only the benefit (the saved fee). (B) supplies the missing half: the course would cost little, because the equipment already exists. (D) is true and might belong somewhere, but it limits the course rather than supporting the claim. (A) and (C) are on the subject of the course but say nothing about cost.
2. (C). The paragraph's claim is that repair skills build confidence. Version (C) frames the source as an authority (twelve years of watching students), embeds the quotation in the writer's sentence, and adds commentary that names the mechanism (each repair proves a problem can be solved). (A) and (B) present the quotation with no explanation of how it supports the claim; (B) also drops the speaker's credentials. (D) paraphrases but removes the attribution's value: "a teacher" gives the reader no reason to trust the claim.
3. (C). The stem asks for commentary, a sentence that links the evidence (a ninety-dollar minimum fee, avoided by one learned repair) to the claim (the course pays for itself). (C) draws that link (one saved fee outweighs the cost of the parts) and extends it across time. (A) restates the evidence as an opinion without connecting it to anything. (B) introduces a different topic, and (D) adds an unrelated fact. Note that (C) uses the comparison the claim depends on (savings versus cost), which is exactly what a skeptical reader would ask about.
The method behind all three. Find the claim the stem points to, decide what that claim still needs (missing evidence, a frame, a link), and choose the answer that supplies exactly that.
Where students lose points
On the exam
The synthesis essay asks you to argue your own position using at least three of the six sources, citing each by its letter or description; a response that draws on fewer can't reach the upper scores in evidence and commentary. All three essays are scored on a defensible thesis, on evidence and commentary together, and on sophistication, and in the synthesis essay sophistication often comes from how you handle sources that complicate your position. Multiple-choice writing questions on drafts test this skill by asking which evidence best supports a given claim, how best to integrate a quotation, and which sentence best explains how evidence supports a claim. Topic 3.6 covers developing the line of reasoning that your paragraphs build together.
Check yourself
Question 1
A student argues that her town should keep its public pool open until 9 p.m. in July. Which sentence best integrates the quotation into her line of reasoning?
- A
"Our busiest hour is the last one," said the pool's manager.
- B
The pool's manager, who has run the sign-in desk for six summers, reports that "our busiest hour is the last one," which means that closing at 8 would cut the hour when most working families can actually come.
- C
The pool is popular. "Our busiest hour is the last one."
- D
According to someone at the pool, the busiest hour is the last one, which is interesting.
Show answer
B
Choice B frames the source as an authority, embeds the quotation in the writer's sentence, and adds commentary that ties it to the claim about later hours. Choice A is tempting because it attributes the quotation correctly, but it never says what the quotation proves.
- A
Question 2
A synthesis essay's body paragraph begins: "Source B is about the cost of the new library. Source D is about how many people used the old one." Rewrite the opening as one sentence that makes a claim and uses both sources together. (Assume Source B reports a $4 million cost and Source D reports 120,000 visits a year to the old library.)
Show answer
A strong answer leads with a claim and joins the sources, for example: "The new library's $4 million cost (Source B) looks smaller once you count who would use it: the old building already draws 120,000 visits a year (Source D), so over twenty years the cost works out to under $2 a visit, a small price for a building residents already use this heavily."
Synthesis organizes by idea: the writer's claim comes first and both sources serve it, combined in a way that says something neither says alone. Listing what each source is about is a summary of the packet.
Question 3
In a synthesis essay on whether a town should build a fenced dog park, which of the following sentences most needs a citation?
- A
Many people in town own dogs.
- B
I think a dog park would give owners a place to exercise their dogs legally.
- C
Animal control logged 230 complaints about off-leash dogs in town parks last year.
- D
Dogs need regular exercise.
Show answer
C
A specific figure taken from the packet belongs to its source and must be cited even when you restate it in your own words. Choice B is the writer's own claim, and A and D are general knowledge; citing them would be harmless but isn't required.
- A
Question 4
A student arguing that her school should keep its daily silent-reading period finds an opposing source (Source C): a teacher writes that "students spend half the period pretending to read." Write two sentences that use this source as a concession and then answer it.
Show answer
A strong answer grants the point and shows why the claim survives it, for example: "The teacher is right that many students spend half the period pretending to read (Source C). But that leaves the other half, which for many of them is the only time all day they read anything longer than a caption, and a period with half its value is still worth more than none."
A concession grants the source's point outright, cites it, and then shows that it doesn't decide the question. Dismissing the source or ignoring it would leave the strongest objection unanswered.