Question 47·Medium·Command of Evidence
While excavating a limestone cave on the Iberian Peninsula, archaeologists found twelve shallow, bowl-shaped depressions carved into a single rock shelf. Each depression contained a thin residue of red ochre pigment. After laboratory testing showed that the chemical composition of the pigment is virtually the same in every depression, one archaeologist concluded that the identical chemical makeup of the ochre residue suggests that one individual prepared pigment in all of the depressions at the same time.
Which finding, if true, would most directly weaken the underlined claim?
For SAT “weaken the claim” questions, first clearly separate the evidence from the conclusion in the passage. Then ask: “What assumptions connect this evidence to that conclusion?” Look for answer choices that either (1) show the evidence could have another cause (an alternative explanation), or (2) show the evidence is less reliable or less relevant than the author believes. Ignore choices that are merely interesting background or that add information but do not undercut the logical link between evidence and conclusion.
Hints
Find the conclusion and the evidence
Underline or note the conclusion (what the archaeologist is claiming) and the evidence (what the lab found). Ask yourself: what is the logical link between them?
Ask: what must be true for that logic to work?
The archaeologist is assuming that identical chemical makeup can only happen if one person prepared the pigment at one time. Think about how that assumption could be wrong.
Look for an alternative explanation for the lab result
Which choice suggests a way that all the residues could show the same chemical composition now, even if they were not prepared by one individual at the same time?
Watch out for off-topic details
Ignore choices that just add interesting information about the cave, the region, or traditions unless they clearly affect whether identical chemical composition proves the archaeologist’s conclusion.
Step-by-step Explanation
Restate the claim being tested
The archaeologist’s conclusion is: because all the ochre residues now have identical chemical composition, one individual prepared all the pigment at the same time.
So the reasoning is:
- Evidence: the residues are chemically the same now.
- Conclusion: they must have been made by the same person at the same time.
Identify what would weaken the reasoning
To weaken the claim, the new information should show that the evidence (matching composition) does not necessarily imply a single person prepared all the pigment at one time.
The most direct way is to provide an alternative explanation for why the residues test the same today.
Find the choice that breaks the evidence-to-conclusion link
The best weakening information would show that residues that started out different could later end up looking chemically identical due to something that happened after the pigment was made.
Select the option that provides that alternative explanation
The option about groundwater explains how a natural process could make originally different residues become chemically indistinguishable, so identical composition today would not prove “one person, one time.”
Therefore, the correct answer is: “Experiments show groundwater can, over time, make ochre residues that once differed in composition become chemically indistinguishable.”