hypothesis
/haɪˈpɒθ.ɪ.sɪs/- 1.
A proposed explanation for something, based on limited evidence, that you plan to test. Scientists form a hypothesis before running experiments to see if it is correct.
- The researcher's hypothesis was that sleep deprivation affects memory.
- We need data to support or reject this hypothesis.
- She formed a hypothesis and then designed an experiment to test it.
- 2.
In general use, a suggested idea or tentative explanation used as a starting point for thinking or discussion, even outside a formal scientific setting.
- His hypothesis was that poor communication caused the project to fail.
- Let's work from the hypothesis that prices will rise next quarter.
Adinary Nuance
A hypothesis is not the same as a theory: a hypothesis is an untested, proposed explanation, while a theory has already been tested and backed by strong evidence — so calling evolution "just a theory" actually undersells it. A conjecture is a less formal guess, often used in mathematics or everyday talk, without the structured intent to test it. An assumption is something you accept as true without questioning or testing at all, making it weaker and less deliberate than a hypothesis. In academic and IELTS writing, "hypothesis" signals a precise, testable claim — using it correctly instead of "idea" or "guess" will immediately raise your register.
In other languages
- Vietnamese
- Giả thuyết
- Spanish
- Hipótesis
- Chinese
- 假设
- Japanese
- 仮説
- Korean
- 가설
Etymology
From Greek "hupothesis," meaning "basis" or "supposition," built from "hypo" (under) + "thesis" (placing). It entered English in the late 16th century through Latin, originally in philosophy and then scientific writing.
Common phrases
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Frequently asked questions
- What is the difference between a hypothesis and a theory?
- A hypothesis is an untested idea you plan to investigate. A theory is a well-supported explanation that has already been tested with strong evidence. In science, a theory is actually more reliable than a hypothesis, not less.
- Is 'hypothesis' only used in science?
- No. It is also common in philosophy, law, business analysis, and general academic writing. Anytime you propose an explanation that needs to be checked, you can call it a hypothesis.
- Can I use 'hypothesis' in IELTS writing?
- Yes, and it is a strong choice. Using 'hypothesis' instead of 'guess' or 'idea' raises the academic register of your writing, which is rewarded in IELTS Task 2 and Academic Task 1 responses.
- What does 'null hypothesis' mean?
- A null hypothesis is the default assumption that there is no effect or no relationship between variables. Researchers design experiments to try to disprove it, which is standard practice in statistics and research.