What is a hypothesis?

A hypothesis is a testable prediction derived from a theory, which means it is formulated based on prior knowledge or existing theories and can be empirically tested through research. This fundamental aspect of a hypothesis is crucial because it allows researchers to design experiments or studies to confirm or refute the prediction. For example, if a theory suggests that sleep impacts memory retention, a hypothesis might be that individuals who sleep for eight hours will perform better on memory tests compared to those who do not get enough sleep. The ability to test such predictions is what makes a hypothesis integral to the scientific method, guiding research and contributing to the development of knowledge.

In contrast, a confirmed theory based on abundant evidence lacks the speculative and testable nature that characterizes a hypothesis. An untestable statement about relationships does not possess the required format to be scientifically useful, as hypotheses must be operationalized into measurable variables. Lastly, a vague assertion regarding behavior fails to provide the clarity and specificity needed for research, thus not serving as a functional hypothesis.