A hypothesis and a theory are both cornerstones of the scientific method, but they represent different stages of scientific understanding. The key difference lies in their development and the level of evidence supporting them.
Hypothesis vs. Theory: A Detailed Comparison
| Feature | Hypothesis | Theory |
|---|---|---|
| Definition | A testable explanation for a specific phenomenon. | A well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses. |
| Development | Constructed before research. | Developed after substantial research and data analysis. |
| Evidence | Lacks supporting evidence at the outset. | Supported by a significant body of evidence. |
| Purpose | To guide research and experimentation. | To explain and predict phenomena. |
| Scope | Narrow in scope, addressing a specific question. | Broad in scope, explaining a wider range of phenomena. |
| Level of Certainty | Tentative and speculative. | Highly probable, but still open to revision. |
| Example | "If I increase the amount of water, then plant growth will increase." | "The theory of evolution explains the diversity of life on Earth through natural selection." |
Elaborating on the Differences
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Hypothesis: Think of a hypothesis as an educated guess. It's a proposed explanation for a specific, limited set of phenomena. Before any research takes place, scientists formulate a hypothesis to guide their investigation. The hypothesis is then tested through experiments and observations.
- Example: A researcher might hypothesize that a new drug will lower blood pressure. This hypothesis can then be tested through a clinical trial.
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Theory: A theory is a much broader and more comprehensive explanation than a hypothesis. According to the reference, "a theory... is supported by evidence: it's a principle formed as an attempt to explain things that have already been substantiated by data." A theory has undergone rigorous testing and is supported by a substantial body of evidence. It explains not just a single phenomenon, but a wider range of related phenomena.
- Example: The theory of gravity explains not only why objects fall to the ground, but also the orbits of planets and the tides of the ocean.
In Summary
- Example: The theory of gravity explains not only why objects fall to the ground, but also the orbits of planets and the tides of the ocean.
A hypothesis is a starting point, a proposed explanation awaiting testing. A theory is the result of extensive testing and evidence, a well-supported explanation of the natural world. A hypothesis can be disproven through experimentation, while a theory is more resistant to being disproven due to the significant amount of evidence supporting it, though it can be refined and updated with new evidence.
