A comparison of the maximum likelihood estimators under ranked set sapling some of its modifications

This paper compares the maximum likelihood estimators (MLEs) of the parameters of the location-scale parameter family of distributions, under the methods of ranked set sampling (S.L. Stokes, Annals of the Institute of Statistical Mathematics 47 (3) (1995) 465), median ranked set sampling and extreme ranked set sampling (A.-B Shaibu, H.A. Muttlak, Annals of the Institute of Statistical Mathematics, submitted), and percentile ranked set sampling. Several distributions have been considered and the estimators are compared based on their asymptotic relative precision with respect to the corresponding simple random sample estimators.