What is a hypothesis?

A hypothesis is fundamentally a testable prediction that is crafted based on observations and prior knowledge. It serves as a starting point for scientific investigation, guiding the experimental process by providing a clear expectation of what outcomes may occur under certain conditions. This prediction is formulated to be tested empirically, allowing scientists to gather data that can confirm or refute the hypothesis.

In scientific practice, a good hypothesis is specific and makes predictions that can be validated or challenged through experimentation. It often follows the structure of an "if-then" statement, establishing a relationship between variables to be tested in a controlled setting. The ability to test and measure the outcomes is what distinguishes a hypothesis from a mere guess or a statement of fact.

This definition underscores why other provided options do not accurately describe a hypothesis. A definitive conclusion based on data represents the end result of the scientific process, rather than a preliminary prediction. An established scientific fact refers to findings that have been repeatedly tested and accepted within the scientific community, moving beyond the status of a hypothesis. A theory with no basis in evidence does not align with the nature of scientific inquiry, as a hypothesis must be grounded in existing knowledge and observations to be considered scientifically valid.