Document Type : Original Paper


1 Department of Statistics, Faculty of Mathematical Sciences, Vali-e-Asr University of Rafsanjan, Rafsanjan, Islamic Republic of Iran

2 Department of Statistics, College of Sciences, Shiraz University, Shiraz, Islamic Republic of Iran


This article aims to provide a simple robust method to test the parameters of a normal population by using the new diagnostic tool called the “Forward Search” (FS) method. The most commonly used procedures to test the mean and variance of a normal distribution are Student’s t test and Chi-square test, respectively. These tests suffer from the presence of outliers. We introduce the FS version of these tests that is not affected by the outliers. The performances of these procedures are illustrated by some simulation studies and a real data example.