LSAT Reading Comprehension: Additional Evidence

What the Question Asks

Additional Evidence questions frame the passage as a piece of reasoning under evaluation and ask what kind of evidence is in play. Sometimes you're asked what the passage cites as evidence for its claim. Sometimes you're asked what data, if collected, would be relevant to evaluating a hypothesis. Sometimes you're asked which question the passage has enough information to answer. In all cases, you're reasoning about the relationship between data and claim.

Four skills are tested. Evidential relevance — understanding what counts as meaningful evidence for a particular claim or hypothesis. Evidence identification — locating what the passage presents as supporting evidence. Data-claim matching — connecting specific types of data to the specific claims they could help evaluate. And scientific reasoning — understanding what observations, experiments, or data sources would bear on a hypothesis.

Kinds of Helpful Evidence

Because the answer choices describe types of evidence, it helps to have a vocabulary of the kinds that typically show up. Four recur. An observation: a direct sighting or measurement of the phenomenon in question, useful when the claim is about whether something exists or happens. A study: a controlled comparison or experiment, useful when the claim is about causation or correlation. A comparison: data from an analogous case in a different context, useful when the claim's generality or exclusivity is at stake. A demographic data point: population-level statistics about distribution or frequency, useful when the claim is about prevalence or trends.

The correct answer is whichever of these evidence types bears most directly on the targeted claim. Note that "bears on" is broader than "strengthens" — relevant evidence can confirm or refute. The question isn't asking which evidence would prove the claim; it's asking which would count if collected.

The Variations You'll See

With only 7 questions in the corpus, each example is close to its own variant, but four recognizable subtypes emerge.

Variation A — "Passage presents X as evidence of..." (2 questions, 29%). Asks what the passage itself cites as evidence for a claim — essentially a detail question about evidential structure. "Which one of the following is presented by the author as evidence of X?" Looks backward into the passage rather than forward into hypotheticals. You identify which of the passage's stated facts the author deploys in support of a specific claim.

Variation B — "Data most relevant to evaluating..." (2 questions, 29%). Asks what kind of data would help evaluate — not necessarily support — a claim or hypothesis. "Data from which one of the following sources would be most relevant to evaluating [person]'s hypothesis?" "Relevant to evaluating" is broader than "would strengthen" — the evidence might confirm or refute. You identify what type of data would be informative.

Variation C — "Passage contains information to answer..." (2 questions, 29%). Asks which question the passage provides enough information to answer. "The passage contains information that most helps to answer which one of the following questions?" A meta-question about what the passage's evidence can address. It overlaps with Specific Reference but is classified as Additional Evidence when the focus is evidential sufficiency rather than factual retrieval.

Variation D — "Evidence that would lend support to..." (1 question, 14%). Asks what type of evidence would support a specific proposal or model. "Which one of the following is most clearly an example of the kind of evidence that would lend support to the author's proposal in [section]?"; "It can be inferred that the author would be more likely to endorse [model] if this model were supported by which one of the following kinds of evidence?" Closest to Strengthen, but frames the task as identifying the kind of evidence rather than a specific hypothetical fact.

How to Approach the Question

Step 1 — Pin down the target claim. Identify which specific claim, hypothesis, or proposal the question is asking about. Add-on questions often target a particular passage figure's hypothesis, not the passage's main argument.

Step 2 — Decide which variation you're in. Variation A is a detail question; the answer is in the passage. Variations B, C, and D are hypothetical; the answer describes evidence that would bear on a claim if collected.

Step 3 — Ask what kind of evidence would actually bear on the claim. Think through the four types — observation, study, comparison, demographic data — and mentally test which would be most informative given the nature of the claim.

Step 4 — Check each choice for direct relevance. Topical relevance is not evidential relevance. Ask of each choice: would a researcher who collected this data actually learn something about the target claim? If the answer is "only indirectly," eliminate it.

How the Correct Answer Is Built

For Variation A, the correct answer simply names evidence the passage explicitly cites. For Variations B, C, and D, the correct answer describes data or evidence that bears directly on the targeted claim, genuinely helps evaluate it (not just tangentially relates), is the most relevant of the five options, and is specific enough to be actionable rather than vague.

Stems average 23.7 words and vary significantly because the type spans multiple subtypes. Answer choices average 16.0 words and describe types of evidence, data sources, or questions — ranging from the concrete ("tabulation of the number of butchered horse bones") to the more abstract ("evidence of controlled burning practices").

The full corpus of 7 questions: PT38 Q4 (difficulty 3) — evidence the passage cites for pre-European controlled burning in tropics. PT51 Q13 (difficulty 4) — evidence to support the view that Late Heavy Bombardment was limited to Earth/Moon. PT66 Q22 (difficulty 4) — information the passage can answer about a characteristic of jazz also in other African American works. PT79 Q17 (difficulty 3) — evidence lending support to the author's proposal about forest clearings. PT79 Q20 (difficulty 3) — evidence the author would want for a resource-procurement model for clearings. PT84 Q25 (difficulty 3) — evidence supporting the authors' claim about biological adaptation speed. PT85 Q14 (difficulty 4) — data relevant to evaluating Olsen's hypothesis about Botai horse domestication. The type concentrates in recent PrepTests (PT79, PT84, PT85), with earlier appearances scattered.

Common Wrong-Answer Traps

Trap 1 — Topically related but evidentially irrelevant. The choice describes data about the passage's subject that doesn't actually bear on the specific claim. If the hypothesis is about horse domestication, data about ancient climate patterns in the region is related (same topic, same region) but not evidentially relevant. Defense: ask whether the data would move your confidence in the specific claim, not whether it mentions the right subject.

Trap 2 — Evidence for wrong claim. The choice would help evaluate a different claim in the passage, not the one the question targets. Passages often contain multiple claims and hypotheses; wrong answers exploit the confusion. Defense: be specific about which claim the stem names before reading choices.

Trap 3 — Too vague to be evidence. The choice is worded so generally that it wouldn't actually distinguish between competing hypotheses. Defense: ask whether the evidence, if found, would yield a determinate update one way or another.

What Makes the Hardest Versions Hard

Additional Evidence has a base difficulty of 3. Questions stay at 3 when the passage clearly identifies its evidence and you're asked to locate it. They rise to 4 when the question asks for hypothetical evidence and you have to evaluate evidential relevance from multiple choices. They climb to 5 when the evidential relationship is indirect, or when the hypothesis being evaluated is complex enough that multiple types of data look relevant at first glance.

Single vs. Comparative Passages

All 7 of 7 questions (100%) appear on single passages. None appear on comparative passages. This is one of the few RC types that has never shown up in a comparative set — in practice, if you're on a comparative passage, you won't see an Additional Evidence question.

Question Stems You'll See

Recognize these stems as evidential-reasoning questions: pin down the target claim, decide whether the answer is in the passage or hypothetical, and evaluate each choice for direct relevance to the claim.

• "Which one of the following is presented by the author as evidence of [X]?"
• "Data from which one of the following sources would be most relevant to evaluating [person]'s hypothesis?"
• "Which one of the following is most clearly an example of the kind of evidence that would lend support to [X]?"
• "The passage contains information that most helps to answer which one of the following questions?"
• "Which one of the following is most clearly an example of the kind of evidence that would lend support to the author's proposal in [section]?"
• "It can be inferred that the author would be more likely to endorse [model] if this model were supported by which one of the following kinds of evidence?"