Outlier (nonfiction)

Example of two-dimensional outliers. Point labeled O1 and points labeled O2 deviate significantly from regions labeled G1 and G2.

In statistics, an outlier is an observation point that is distant from other observations.

An outlier may be due to variability in the measurement or it may indicate experimental error; the latter are sometimes excluded from the data set.

Outliers can occur by chance in any distribution, but they often indicate either measurement error or that the population has a heavy-tailed distribution.

In most larger samplings of data, some data points will be further away from the sample mean than what is deemed reasonable. This can be due to incidental systematic error or flaws in the theory that generated an assumed family of probability distributions, or it may be that some observations are far from the center of the data.

Outlier points can therefore indicate faulty data, erroneous procedures, or areas where a certain theory might not be valid.

However, in large samples, a small number of outliers is to be expected (and not due to any anomalous condition).

In the News

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  Allumette emflammée, symbol of Les Empyrées, accidentally sets fire French Revolution.

Fiction cross-reference

• Database Database - an English language nursery rhyme.
• Les Empyrées

Nonfiction cross-reference

• Data (nonfiction)
• French Revolution (nonfiction)
• Mathematics (nonfiction)
• Statistics (nonfiction)

External links:

• Outlier @ Wikipedia