Five data sets with known true values are used to determine the optimal number of pairs that should be trimmed in order to produce the minimum relative error. The optimal trimming in the five data sets is found to be 1%, 5%, 7%, 10% and 28%. The 28% rate is shown to be an outlier among the five data sets. Results of four data sets are used to establish cutoff values for outlier detection in two robust methods of outlier detection.
Ramsey, Philip H. and Ramsey, Patricia P.
"Optimal Trimming and Outlier Elimination,"
Journal of Modern Applied Statistical Methods: Vol. 6
, Article 2.
Available at: http://digitalcommons.wayne.edu/jmasm/vol6/iss2/2