ACT® · Science: The Three Passage Formats
Conflicting Viewpoints Passages
A Conflicting Viewpoints passage gives two or more scientists who share the same data but disagree because they start from different assumptions. Reading it well means tracking each scientist's claim and the specific evidence behind it, not which one sounds more confident.
Two scientists can stare at the same fossil bed and walk away with opposite stories because they aren't disagreeing about what they saw. They're disagreeing about what to assume before they even start interpreting it. One treats a layer of sediment as a single flash flood; another treats the same layer as years of slow seasonal buildup. The measurements match. The premises don't. That's the entire engine of this passage type: same observations, different starting assumptions, so different conclusions follow by ordinary logic.
Reading one of these passages means pulling out, for each scientist, one sentence that states their claim and one or two pieces of evidence or reasoning they lean on to defend it. Scientist 1 might argue a current's slowdown will warm shelf water. Scientist 2 might argue upwelling will cool it. Neither is reading the thermometer wrong. They disagree about which process dominates. Once you have both claims lined up side by side, most questions just ask you to test new information against each one and see which claim it fits.
Length is a trap here. A passage often gives one scientist three sentences and the other three paragraphs, and it's tempting to assume the longer explanation is the one the test wants you to believe. It isn't. Both get evaluated the same way, by what evidence actually supports each claim. This passage type sits apart from Data Representation and Research Summaries because there's no single experiment to read correctly. Add a third scientist with a different premise again, and the task doesn't change, just the number of claims you're sorting evidence against.
Key terms
- Premise
- An assumption a scientist builds their model on, rather than something directly measured.
- Claim
- The specific prediction or conclusion a scientist states about the shared data.
- Shared data
- The measurements or observations both scientists agree on, even though they interpret them differently.
- Supporting evidence
- The reasoning or facts a scientist cites to defend their claim, which is what questions actually test.
Watch it explained
- How it worksHow does a Conflicting Viewpoints passage build two models on different premises rather than different data?
- How it worksWalk me through reading Scientist 1 and Scientist 2 as two claims plus the evidence each one leans on.
- Common mistakeWhy isn't the longer of two competing viewpoints the one the ACT quietly treats as correct?
- Worked exampleFind which of two viewpoints a 0.8 degree C ocean warming supports when one predicts warming and the other cooling.
- Going furtherWhat happens to a viewpoints question when a third scientist is added who agrees with neither of the first two?
Check yourself
End of topic.