ACT Science: Recognize Valid Hypotheses and Predictions

A valid hypothesis is (1) testable (you can design an experiment to confirm or refute it), (2) based on observation (not pure guessing), and (3) falsifiable (it could be wrong, and you could prove it). "Higher temperature increases reaction rate" is valid: you can test it, it is based on chemistry knowledge, and it could be false if you find evidence to the contrary. "Chemistry is fun" is invalid: not testable, subjective, not falsifiable. ACT tests whether you can distinguish valid from invalid hypotheses; students who understand the three criteria answer these questions with 90% accuracy.

Example invalid hypothesis: "Evolution happens because God wills it." This is not testable through experimentation; it is a belief, not a scientific hypothesis. Valid version: "Organisms with certain traits survive and reproduce more successfully in a given environment, leading to trait prevalence in future generations." This is testable through observation and experiment.

Red flag 1: The hypothesis is based on opinion or belief, not observation. ("Ice cream is bad because I do not like it.") Red flag 2: The hypothesis cannot be tested with any realistic experiment. ("Cats prefer people who think kindly of them.") Red flag 3: The hypothesis is unfalsifiable. ("Everything happens for a reason.") Spot these three red flags and you will instantly identify invalid hypotheses, earning you 1-2 points per Science section.

On your next practice test, read every hypothesis or prediction and ask: "Is this testable? Is it based on observation? Could it be false?" If you answer "no" to any, the hypothesis is invalid.

Read five ACT Science passages. For each, identify the hypothesis being tested. Ask: Is it valid? Why or why not? Write one sentence explaining your answer. Check the explanation against the passage. This drill trains your brain to evaluate hypotheses critically, a habit that improves Science reasoning question accuracy by 15-20%.

Do this drill once per week for two weeks. By test day, you will spot invalid hypotheses instantly and defend your answer with confidence.

One or two questions per ACT Science section ask you to evaluate a hypothesis or prediction. Each is worth 1 point. Understanding the three criteria for valid hypotheses nets you 2 easy points per test section, or 2 points total, raising your composite by a fraction of a point.

This week, learn the three criteria. By test day, hypothesis evaluation will feel like second nature.