hypothesis

Everyday

1. (science) An idea or guess that explains something and that you can test with an experiment or observation. tree →
2. (formal) Any idea suggested as a starting point for thinking, which may or may not be true. tree →

In the lessons

In science lessons it is a key step of a fair test: question, hypothesis (prediction with reasons), experiment, results, conclusion. It tells the reader that something is not yet proven. Phrases: test a hypothesis, form a hypothesis, the hypothesis was supported.

Examples

• My hypothesis is that plants grow faster in sunlight. tree →
• We tested our hypothesis with a fair test. tree →
• The results did not support the hypothesis. tree →
• A good hypothesis can be proved wrong by an experiment. tree →
• Scientists made a new hypothesis after the surprise result. tree →
• Write your hypothesis before you start the experiment. tree →

Note

Plural hypotheses (say hy-POTH-uh-seez). Adjective: hypothetical. Trap: a hypothesis is not the same as a fact or a theory; a scientific theory is a well-tested explanation, not a guess.