PrepTest 150, Section 4, Question 20

Working the answers

• A

  We learn that the study sought narrow, tilted fracture zones in arid countries. We don't learn that such zones are more common there than elsewhere. Finding something in one setting doesn't establish a comparison with other settings.

• B

  The account doesn't describe reliable studies of other underground resources, but that doesn't establish that none exist. There could be studies of locating oil or other resources that this discussion simply doesn't cover.

• C

  The dry-fracture result is reported without a change of tools. That doesn't tell us what tools a dowser would or would not use for a different target. The passage supplies no basis for the asserted difference.

• D

  We are told the dowsers located a dry fracture zone. We aren't told that the scientists failed to locate one or couldn't do so. Success by one group doesn't establish inability in the other.

• E
  Correct

  Typical studies poorly represent verifiably successful dowsers; this study selected the most successful dowsers. That difference in the study population supports calling it atypical. We don't have to assume typical studies contain no successful people at all. The important contrast is poor representation in the usual study versus deliberate selection of highly successful participants here.