What does hypothesis mean?
A hypothesis is a provisional explanation or interpretation of an observation, phenomenon, or set of facts. It proposes a relationship or cause that can be investigated through reasoning, observation, experimentation, or statistical analysis. In science, a hypothesis is expected to be testable: evidence may support it, weaken it, or rule it out. The word is also used more broadly for an informed conjecture about why something happens, though it often carries a more formal and systematic tone than guess or idea. A hypothesis commonly develops into a theory as it is repeatedly tested and supported by evidence, while remaining distinct from a fact, which has been established rather than merely proposed. The term is especially useful for describing the initial, disciplined stage of inquiry, in which a question is converted into a precise claim that can be examined.
nounA proposed explanation or interpretation of an observation, phenomenon, or set of facts, regarded as a starting point for investigation rather than an established conclusion. In scientific contexts, a hypothesis is a testable proposition that can be supported or challenged by evidence.
- A proposed explanation or interpretation of an observation, phenomenon, or set of facts, especially one that is to be tested scientifically.
- A tentative or speculative idea about the cause or nature of something.
- In statistics, a statement about a population or a model that is evaluated against data.
"The researchers tested the hypothesis that regular exercise can improve memory."
"The initial hypothesis was rejected when the experimental results were analyzed."
"Her hypothesis about the decline in bee populations led to an extensive field study."
The plural changes -is to -es: hypothesis becomes hypotheses.
"The scientists compared several competing hypotheses about the cause of the decline."
A hypothesis is science’s way of turning curiosity into a question that evidence can answer.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does hypothesis come from?
The word comes from Greek hypothesis, formed from hypo- (“under”) and thesis (“placing” or “setting down”), literally suggesting a proposition placed underneath or offered as a basis for discussion. It entered English in the early 17th century and originally referred to a particular proposition or supposition put forward in a discussion of ideas. The word is related to thesis, synthesis, and other English words associated with the Greek root for placing or setting down.
Related word forms
How hypothesis is actually used
In scientific and academic writing, the term usually denotes a testable proposition rather than a mere guess. The distinction between a hypothesis and a broader, more established theory is important, although the boundary can vary by discipline.
Easily confused with hypothesis
A hypothesis is a tentative, testable explanation, whereas a thesis is a central claim or argument, often in a formal piece of writing.
A hypothesis is typically an initial proposition to be tested, while a theory is a more extensively developed and well-supported explanation.