Which statement best expresses the passage’s main idea?

When several explanations fit, inquiry should seek evidence on which their predictions differ while allowing cautious action. (The shadow example shows why discriminating observations, not sheer quantity or precision, help compare rivals without requiring total certainty.)

Why might measuring the same shadow more precisely add little?

Both the pole and crane explanations may predict the same shadow measurement. (If rival causes fit the same length, reducing error in that length does not separate them; a different clue is needed.)

What does “refine” mean in “Later evidence can refine the decision”?

Improve or adjust the decision with greater precision (The decision begins cautiously under uncertainty and can be adjusted as later evidence makes the situation clearer.)

Which clue might reveal a narrow cable in the shadow?

Looking carefully at the shadow’s outline (The second paragraph directly says examining the outline could reveal a cable, which may help distinguish the possible sources.)

Two Explanations, One Shadow: Level 5 Reading Comprehension Questions

A single observation can fit more than one explanation. Imagine finding a long shadow across a courtyard at noon. Perhaps a new pole stands beyond the wall. Perhaps a crane has stopped there for repairs. The shadow alone does not decide between them, even if its length is measured perfectly.

This problem is sometimes called underdetermination: the available evidence does not uniquely determine one account. It does not follow that every account is equally good. Looking at the shadow’s outline may reveal a narrow cable. Checking yesterday’s photograph may show that no permanent pole existed then. Asking whether construction is scheduled may add another independent clue. Each inquiry can favor one explanation, weaken another, or suggest a third.

Nor must inquiry wait until all alternatives disappear. A caretaker who needs to keep people away from a possible work zone can act cautiously while the cause remains uncertain. The action should reflect both the evidence and the cost of being wrong. Later evidence can refine the decision.

The lesson is not that facts are powerless, but that their power depends on the questions put to them. More precise measurement of the same shadow may add little. A differently chosen observation can add much. Good inquiry searches not merely for more evidence, but for evidence that makes rival explanations predict different things.

Comprehension questions