An Alternate Method for Testing the Same Hypothesis (SIN 602)

Science passages often give one experimental setup, then ask you to judge a second, different one. The two can look nothing alike: different instruments, different timing, different materials. None of that matters for whether the second setup tests the same hypothesis. What matters is only two things: does it still manipulate the same variable across the same range, and does it still measure the same outcome. If both survive, the method is an alternate way to test the same idea, even if every tool changed.

The trap is assuming a cheaper or faster method is automatically fine. It isn't, unless whatever it measures still stands for the quantity the hypothesis is actually about. Swapping a balance for a graduated cylinder only works if mass and volume move together for every sample, which requires one shared density. If densities differ, volume stops tracking mass, and the quicker method is measuring something else entirely. Always ask what the new measurement would miss, not just what it saves.

A special case shows up when the original measurement destroys the sample. You cannot measure the same tablet twice if measuring it dissolves it. So a question about change over time forces a design where each time point uses a fresh, matched sample from the same batch, and the trend is read across samples instead of within one. This connects directly to comparing two experiments: once you can judge whether a method is a valid alternate, you can also judge whether two given experiments in a passage are actually testing the same hypothesis or secretly different ones.