Testing For Outliers

Abstract

<p>Several test statistics, which are known, can be used for testing for outliers. Two new statistics T and tc are proposed. T and tc are based on censored and complete samples and are similar to Tiku's T and tc statistics for testing for normality. The distribution of T is closely approximated by the Beta distribution, and the distribution of tc is closely approximated by Student's t distribution. T and tc are also both origin and scale invariant. Besides T and tc are easy to calculate. The statistic T is more powerful than Tietjen and Moore's statistics Lr and Er. The statistic tc is, on the whole, as powerful as Er.</p>