Formulation of a hypothesis may not be required in

Formulation of a hypothesis may not be required in historical studies, which often aim to reconstruct and describe past events.

Fact-finding and descriptive historical work proceeds without a predicted relationship to test.

The survey method frequently frames hypotheses about associations among measured variables.

Experimental studies are built around testing a hypothesis by manipulating a variable.

Correlational studies state a hypothesis about the direction or strength of a relationship.

Even exploratory studies may replace formal hypotheses with guiding research questions.