The Sourdough Starter Log and the Ambiguous Pronoun
A food-science club keeps a shared log of its sourdough starter. On Monday the club secretary writes: "The starter doubled in four hours, which surprised Priya, because she had fed it with the colder water and expected it to rise slowly. This shows that temperature is less important than the club's earlier experiments suggested."
The club's faculty advisor circles two things. First, the word which in the first sentence. Second, the word This in the second sentence. She tells the students that each circled word has more than one possible referent, and that the argument in the second sentence depends on which referent a reader picks. The club has run three prior trials: one with cold water (6-hour rise), one with room-temperature water (4-hour rise), and one with warm water (3-hour rise).
1. Identify the ambiguous referent of *which* and explain how resolving it changes the meaning of the sentence. Then rewrite the sentence so the referent is unambiguous without changing the intended claim.
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Which can attach either to the starter doubling in four hours (an event) or to the starter itself (a thing). If it refers to the event, the sentence says the rise time surprised Priya. If it refers to the starter, it says the starter surprised her, which is odd phrasing but grammatically possible.
The intended claim is clearly that the fast rise surprised her, since she expected a slow rise. A clean rewrite names the event directly:
The starter doubled in four hours, a result that surprised Priya, because she had fed it with the colder water and expected it to rise slowly.
Using a result that forces the event reading and removes the ambiguity. Note that the rewrite must preserve the causal clause (because she had fed it...) - dropping it would change the claim, not just clarify it.
2. The second sentence begins "This shows that temperature is less important..." List the two most plausible referents of *This* and explain which one, if either, actually supports the conclusion.
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Two plausible referents:
- The single Monday observation - one trial in which cold-water-fed starter rose in four hours.
- The comparison with the club's prior trials - cold water (6 h), room temperature (4 h), warm water (3 h).
If This = the single observation, the conclusion is unsupported. A lone fast rise could reflect a warmer kitchen, a more active starter, or a measurement error; it cannot establish a general claim about temperature's importance.
If This = the full set of prior trials, the conclusion is contradicted, not supported. Those trials show a clean temperature effect: colder water, slower rise. Monday's result is the anomaly, not the rule.
So neither referent supports the sentence as written. The fix is to make the referent explicit and to soften the claim to match the evidence - for example: This single result is inconsistent with the pattern in our earlier trials and suggests that another variable may be at work.
3. A student proposes replacing "This shows that" with "This proves that." Evaluate whether that edit improves or worsens the passage, citing the evidence in the setup.
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It worsens the passage. Proves raises the strength of the claim while the evidence stays at a single observation. The setup gives exactly one Monday result against a three-trial background pattern that points the other way (6 h, 4 h, 3 h tracking water temperature). A single contrary data point cannot prove a general claim; at most it raises a question.
The original shows is already too strong for the evidence, so the better edit moves in the opposite direction - toward hedged language such as suggests or is inconsistent with our earlier trials. The judgement the exam tests here is matching claim strength to evidence strength, not choosing the most confident verb.