Approximating the Shapiro-Wilk W-test for non-normality Authors
Received: 15 October 1991 Accepted: 15 October 1991 DOI:
Cite this article as: Royston, P. Stat Comput (1992) 2: 117. doi:10.1007/BF01891203
A new approximation for the coefficients required to calculate the Shapiro-Wilk
W-test is derived. It is easy to calculate and applies for any sample size greater than 3. A normalizing transformation for the W statistic is given, enabling its P-value to be computed simply. The distribution of the new approximation to W agrees well with published critical points which use exact coefficients.
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