The hypothesis meaning in everyday terms is a proposed explanation that you can check: an idea about why something happens, stated clearly enough that a test or observation could show it is wrong. Scientists start experiments with one, detectives work from one, and you use one when you guess why the home internet keeps dropping and then move the router to find out.
The word is a noun. Its plural is hypotheses, and the related verb is hypothesize. This page explains the hypothesis meaning in English with a clear definition, shows how a good one is written, and sets it beside a theory, a prediction and a plain guess.
Entry at a glance
Meaning
A testable idea that tries to explain somethingPart of speech
NounPronunciation
hy-POTH-uh-sis; plural hy-POTH-uh-seezWord forms
hypotheses (plural), hypothesize (verb), hypothetical (adjective)Origin
Greek hypothesis, foundation, literally a placing under; in English from the 1590sClose words
Theory, assumption, premise, conjectureRegister
Formal, academic and scientific; also used in daily talk
Hypothesis meaning: what makes an idea testable
To define hypothesis in one line: it is a starting idea that you put forward so it can be tested. Three things make it a hypothesis rather than just an opinion:
- It explains or predicts something. It says what you think is going on.
- It is testable. There is some way to gather evidence for or against it.
- It could be wrong. A good hypothesis is stated so that a result could prove it false.
In logic and philosophy the word has an older sense: a statement you assume for the sake of argument, to see what follows from it. That is where hypothetical comes from, as in a hypothetical question.
Hypothesis examples in sentences
- Our hypothesis is that students who sleep eight hours score higher on morning quizzes.
- The engineer's first hypothesis was a loose cable, but the fault came back after she replaced it.
- Doctors tested the hypothesis that the rash was caused by a new soap.
- It is only a hypothesis for now; we need more data before we change the plan.
- The team tested three hypotheses and could rule out two of them.
How to write a hypothesis
School science projects often ask for a hypothesis in an if, then form. It names what you change and what you expect to happen:
If plants receive fertilizer once a week, then they will grow taller in a month than plants with no fertilizer.
Tips that make a hypothesis stronger:
- Keep it to one clear claim.
- Name things you can measure, such as height in centimetres or test scores.
- Base it on something you already know, not a random guess.
- Make sure a result could prove you wrong.
In statistics you will also meet the null hypothesis, the default claim that there is no effect or no difference, and the alternative hypothesis, which says there is one. Researchers collect data to see whether they can reject the null hypothesis.
Definition of hypothesis vs theory, prediction and guess
| Word | What it is |
|---|---|
| Hypothesis | A testable explanation, proposed before the evidence is in |
| Theory | In science, an explanation that has passed many tests and rests on wide evidence |
| Prediction | A specific result you expect to see if the hypothesis is right |
| Guess | Any idea, with or without reasons or a way to test it |
| Assumption | Something taken as true without testing it |
In daily speech people often say theory when they mean hypothesis (my theory is the cat ate it). In science the two are very different: a theory is much stronger. Testing a hypothesis often relies on inference and careful attention to bias.
Where the word comes from
Hypothesis comes from Greek hypothesis, meaning base or foundation. It is made of hypo-, under, and thesis, a placing or proposition, so it is something placed under an argument to hold it up. It arrived in English during the 1590s, passing through Late Latin and French. It was first a term of logic and took on its scientific sense in the 1600s.
Using the word: plural, verb and pairings
The plural follows the Greek pattern: one hypothesis, two hypotheses (the ending changes from -is to -es, like crisis and crises). Never write hypothesises as a plural.
The verb is hypothesize (US) or hypothesise (UK and often India): Researchers hypothesized that the drug would lower blood pressure.
Common pairings: test a hypothesis, form a hypothesis, support or reject a hypothesis, a working hypothesis (a temporary idea you act on), and the hypothesis holds. The science and ideas hub collects fellow terms, science among them.
Frequently asked questions
What is the meaning of hypothesis in simple words?
It is an educated guess that you can test. It explains why something might happen, and an experiment or observation can show whether it holds up.
What is the plural of hypothesis?
The plural is hypotheses, pronounced hy-POTH-uh-seez. It follows the same pattern as analysis and analyses.
Is a hypothesis the same as a theory?
No. A hypothesis is a proposal still waiting for solid testing. A scientific theory is an explanation that has survived a great deal of testing and evidence.
Can a hypothesis be proven true?
Evidence can support a hypothesis strongly, but scientists usually avoid saying it is proven. New data could still challenge it, so they say it is supported or not rejected.
What is a null hypothesis?
It is the starting claim in a statistical test that there is no effect or no difference. Researchers try to gather enough evidence to reject it in favor of an alternative.
What is the difference between hypothesis and hypothetical?
A hypothesis is a noun for a testable idea. Hypothetical is an adjective for something imagined or assumed, such as a hypothetical situation used to think through a problem.