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Statistics vocabulary · Sampling

Sample size

Meaning in statistics, with examples

nounCore term

In statistics, sample size means: The number of observations or participants included in a study, usually written as n (or N for the total).

In Turkish: örneklem büyüklüğü, örneklem hacmi

How it is used

Discussed at the planning stage (how many people do we need?) and in limitations sections (the small sample size limits generalisability). A power analysis is the usual way to decide the sample size before collecting data.

Example sentences

  1. With two groups of 64, a total sample size of 128 gives us 80% power to detect a medium effect.

  2. The main limitation of the study is its small sample size (n = 24).

Common collocations

  • determine the sample size
  • small sample size
  • increase the sample size
  • required sample size
  • sampleA smaller group selected from a population and actually studied, so that conclusions about the whole population can be drawn from it.
  • statistical powerThe probability that a test will detect an effect when a real effect of a given size exists; it equals one minus the probability of a Type II error.
  • margin of errorThe amount added to and subtracted from an estimate to form a confidence interval, showing how far the sample result may differ from the true population value.
  • effect sizeA number that shows how large a difference or relationship is, independently of sample size, such as Cohen's d, a correlation coefficient or an odds ratio.

This word in other fields

The same English word can have a different meaning in another field:

More terms: Sampling

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