PrepTest 128, Section 1, Question 22

Working the answers

• A

  This changes the implication. The writer isn't arguing that many fundamental results are unreliable or contaminated. The model could instead explain why a failed replication doesn't automatically discredit an earlier result.

• B
  Correct

  This gives the mechanism behind our prediction. Some scientists who can't repeat a result might be dealing with systems where tiny differences in starting conditions radically change the outcome. Their failed replications could reflect the nature of those systems. Notice “might”: the final paragraph makes this possibility conditional on other such systems existing.

• C

  “Never” turns a possible problem in some systems into a rule about all experimental results. The model doesn't show that no experiment can ever be replicated.

• D

  The writer suspects other systems exist, but doesn't establish that most systems scientists study are like this. That is much broader than the evidence supports.

• E

  This is the principle introduced at the beginning. The rest of the discussion raises a possible challenge to it. Treating it as the conclusion reverses the direction of the argument.