Meaning & use
null hypothesis
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Meaning
nouncountabletechnicalspecialist
In statistics, the default assumption that there is no effect, difference, or relationship, which researchers test against the data.
Grammar: Usually used with 'the': 'the null hypothesis'. It has a plural form 'null hypotheses'.
Patterns
- the null hypothesis
- reject the null hypothesis
- fail to reject the null hypothesis
- test the null hypothesis
The null hypothesis states that the new drug has no effect compared with a placebo.
If the results are unlikely under the null hypothesis, researchers may reject it.
In this experiment, the null hypothesis was that there would be no difference between the two groups.
Word forms
| plural | null hypotheses |
|---|
Common combinations
- reject the null hypothesis
- The data were strong enough to reject the null hypothesis.
- fail to reject the null hypothesis
- Because the evidence was weak, they failed to reject the null hypothesis.
- test the null hypothesis
- Scientists test the null hypothesis using statistical methods.
- under the null hypothesis
- Under the null hypothesis, the observed difference would be very unlikely.
Synonyms and how they differ
- default assumption
- A general phrase for any starting assumption; 'null hypothesis' is the specific statistical term for the no-effect assumption.
- H0
- A common written symbol for the null hypothesis in statistics; it is not used in ordinary speech.
Opposites
Word family
- hypothesis noun
- A proposed explanation or idea that can be tested.
- hypothesize verb
- To suggest an idea as a possible explanation.
Commonly confused: null hypothesis or alternative hypothesis?
null hypothesis vs alternative hypothesis
The alternative hypothesis is the opposite of the null hypothesis: it says there is an effect or difference. The null says there is none.
Practice
In a statistical test, what does the null hypothesis usually say?
Choose one answer.
The null hypothesis is the default assumption that there is no effect or difference. Option A describes the alternative hypothesis, not the null.
Make it your own
Write a sentence using “null hypothesis”, then check it and compare it with the examples above.