Short on time? This page is the recap. For explanations and worked examples, use the full study guide.
Recap
- Evidence and sources will either support, complement or contradict a writer’s thesis.
- Supporting evidence backs the claim directly. Complementary evidence adds context, a related example or another angle that extends it. Contradictory evidence cuts against it.
- Contradictory evidence is not something to hide: qualify, concede, rebut or refute.
- Name the relationship, use evidence with commentary, and keep the source’s claim distinct from your own.
Key relationships
| Relationship | Job in the argument | Typical commentary |
|---|---|---|
| Supports | Proves the claim | “This shows that…” |
| Complements | Extends or deepens | “This matters because it also…” |
| Contradicts | Tests the claim | “This is true, but…” or “This overlooks…” |
| Response to contradiction | Move |
|---|---|
| Qualify | Narrow my claim so the evidence no longer contradicts it |
| Concede | Accept all or part of the evidence and say what follows |
| Rebut | Offer a contrasting view or alternative evidence |
| Refute | Demonstrate with evidence that the contradicting claim is invalid |
Checking a source
- What does it claim, and how strong is its evidence?
- Who produced it, and why?
- Does it bear directly, partly or loosely on my thesis?
- Which role does it play? (support, complement, contradict)
Public-domain anchor
Henry David Thoreau, Walden (1854): “I went to the woods because I wished to live deliberately, to front only the essential facts of life…” First-hand experience offered as evidence for his claim about simple living. It is vivid and specific, though a critic could say that one person’s experiment is limited as evidence of what is typical.
Worked mini-example
Thesis (Marlbridge): “Schools should start later.”
- Supports: “Pupils in a pilot reported 40 more minutes of sleep.”
- Complements: “Teachers noted that first lessons were calmer.”
- Contradicts: “Bus operators said later starts raised costs.”
Use: lead with the sleep data and comment on its effect on learning; use the calmer lessons to broaden the case; concede the cost and qualify the claim (“provided the transport costs can be met”).
Mistakes to avoid
- Treating all evidence as support.
- Dropping in a quotation without commentary.
- Ignoring strong contradictory evidence.
- Using a complement as if it proved the main claim.
- Using evidence that does not bear on the thesis.
- Mixing the source’s claim with your own interpretation.
Quick self-check
- Does “A second study found the same effect in another city” support, complement or contradict the thesis? (It supports: it bears directly on the claim.)
- How is a complementary source different from a supporting one? (It adds context or a new angle rather than directly proving the claim.)
- Name two ways to respond to contradictory evidence. (Any two: qualify, concede, rebut, refute.)
Next: practice questions.