What defines a scientific theory?

A scientific theory is defined as a well-substantiated explanation of an aspect of the natural world. This means that it is based on a body of evidence collected through observation, experimentation, and rigorous testing. A theory provides a cohesive framework that integrates a wide range of facts and findings, allowing scientists to explain phenomena and make predictions about future observations. The strength of a scientific theory lies in its ability to withstand repeated testing and to be updated with new evidence, which distinguishes it from mere speculation or untested ideas.

In contrast to this definition, other options describe different concepts. A hypothesis, while it can lead to a theory if rigorously tested and supported by evidence, is not itself a well-formed theory; it is more of an initial, tentative explanation. An untested assumption does not meet the criteria for scientific rigor and lacks the empirical support necessary to be classified as a theory. Lastly, characterizing a theory as a temporary solution misrepresents its foundational role in science, as theories tend to be stable and well-supported frameworks rather than stopgap measures. Thus, the most accurate representation of a scientific theory is that it serves as a comprehensive explanation rooted in substantiated evidence.