Impact of New Information on Claims and Arguments
What you must be able to do
Decide how a hypothetical fact would affect the passage's reasoning: strengthen, weaken, leave unaffected, or resolve an ambiguity the passage flags.
Concepts to master
- Find the load-bearing claim. Identify the conclusion the author most needs and the evidence supporting it. New information matters only if it touches that link.
- Strengthen versus be consistent with. A fact that merely does not contradict the argument is not support. To strengthen, the fact must make the conclusion more probable by supplying a missing link or blocking an objection.
- Weaken by attacking the link. The strongest weakeners show that the evidence is equally compatible with an alternative explanation, or that the alleged cause occurred without the effect.
- Resolution questions. When the passage presents a puzzle or conflicting findings, the correct new fact explains both sides rather than favoring one.
Traps
Interesting but irrelevant facts (they concern background detail, not the conclusion), facts that affect a premise the author never relies on, and choices that confuse "compatible with" for "supports."
Rule of thumb and worked example
Restate the argument as "because E, therefore C." Then ask of each option: does this make E less supportive of C, more supportive, or neither?
Example: an author argues a decline in a fish population was caused by a new dam, citing that the decline began the year the dam closed. A fact showing the same decline began two years earlier upstream of the dam weakens the claim by separating cause from effect. A fact showing the dam altered water temperature is relevant only if the argument already links temperature to the fish - otherwise it is interesting and irrelevant.