statistics Statistics (from German language, German: ', "description of a State (polity), state, a country") is the discipline that concerns the collection, organization, analysis, interpretation, and presentation of data. In applying statistics to a s ...

, a polykay, or generalised k-statistic, (denoted

k_

) is a statistic defined as a

linear combination In mathematics, a linear combination or superposition is an Expression (mathematics), expression constructed from a Set (mathematics), set of terms by multiplying each term by a constant and adding the results (e.g. a linear combination of ''x'' a ...

of sample moments.

Etymology

The word ''polykay'' was coined by American mathematician

John Tukey John Wilder Tukey (; June 16, 1915 – July 26, 2000) was an American mathematician and statistician, best known for the development of the fast Fourier Transform (FFT) algorithm and box plot. The Tukey range test, the Tukey lambda distributi ...

in 1956, from ''poly'', "many" or "much", and ''kay'', the phonetic spelling of the letter "k", as in k-statistic.Tukey, J. W. (1956.) "Keeping Moment-Like Computations Simple", ''Ann. Math. Stat.'', 27:37–54.

References

{{Statistics-stub Symmetric functions Statistical inference