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.
Understand what it means to weaken this claim
To directly weaken this claim, a new finding should do one of these:
- Show that the evidence (identical composition) could be explained in another way.
- Show that identical composition does not reliably prove “one person, one time.”
We are not just looking for more facts about the cave; we need something that makes the archaeologist’s conclusion less believable.
Look for an alternative explanation for the identical composition
A powerful way to weaken an argument like this is to show that the observed result (all residues chemically the same) could happen even if the conclusion is false.
Here, that means: a choice showing that different pigments, made by different people or at different times, might end up with the same composition because of some later process or influence.
Evaluate each option against that standard
Now check each option:
- An answer that just mentions other artifacts (like stone flakes) does not explain how different pigments could become chemically identical.
- An answer about what people do in a different cave does not address the chemistry of these residues.
- An answer about the distance to the nearest source of ochre might explain why they used similar material, but it does not show a problem with the chemical test or its interpretation.
- The remaining answer describes a natural process that can make originally different ochre residues become chemically indistinguishable over time, which means the present-day identical composition does not prove they were originally the same batch prepared by one person at one time.
Therefore, the correct answer is: “Experiments demonstrate that groundwater seeping through limestone over long periods can make ochre residues that originally differed in composition become chemically indistinguishable.”