What is a directional hypothesis?

• A. A hypothesis predicting no relationship between variables.
• B. A hypothesis predicting a relationship in a specific direction.
• C. A hypothesis about the direction of sampling error.
• D. A hypothesis with multiple directions of effect.

Answer: (B)

A directional hypothesis is a statement that predicts the specific direction of the relationship or difference between two variables. It reflects a one-tailed approach, where you expect, for example, that as one variable increases, the other increases (or decreases), rather than just predicting that a relationship exists. Because you commit to a direction, the statistical test is concentrated in that one tail, which can increase the power to detect an effect in the predicted direction but won’t detect effects in the opposite direction. This requires a solid theoretical rationale or prior evidence to justify the directional claim. An example would be predicting that increasing study time leads to higher exam scores.