AWWA JAW39272
Journal AWWA - Statistical Procedures for Corrosion Studies
Journal Article by American Water Works Association, 07/01/1995
Wysock, Barbara M.;Sandvig, Anne M.;Schock, Michael R.;Frebis, Christopher P.;Prokop, Boris
Full Description
Decision-makers evaluating corrosion treatment alternatives under the Lead and Copper Rule need the statistical tools to chose the optimum treatment from pipe loop studies. In many cases, the data generated by pipe loop studies do not follow a normal distribution; therefore, nonparametric statistics apply. Techniques that are discussed include determination of data normality using the Kolmogorov-Smirnov and chi-square tests, determination of stabilization using the Spearman coefficient, and comparison of treatments using the Wilcoxon signed ranks or rank sum test. Other data issues that are important to evaluating corrosion studies include determining sample size and frequency, determining the confidence and accuracy of results, and evaluating data outliers. Includes 11 references, tables, figures.