What Is a Research Hypothesis?

Looking for the full method? Read the detailed guide: How to Write a Testable Research Hypothesis.

A research hypothesis is a specific, testable prediction about the relationship between variables, formed before data are analysed. In statistical testing it is usually paired with a null hypothesis of no difference or association.

Example

Invented for teaching: "Adults who walk for 12 weeks will have a lower mean systolic blood pressure than adults receiving usual care." This names the groups, the outcome and the direction of the expected difference.

Common misunderstanding

A hypothesis is not a proven fact and not the same as a research question or an aim. Also, failing to reject the null hypothesis does not prove that it is true. Not every study needs a hypothesis: descriptive studies often have objectives instead.

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See How to Write a Testable Research Hypothesis.

This page is general educational information about research methods. It is not medical, legal or regulatory advice; follow your institution's ethics board and your target journal's instructions.