An investigation into the use of ranked set sampling on grass and grass‐clover swards

Abstract

Four experiments were conducted to assess the performance of ranked set sampling relative to random sampling for the estimation of herbage mass and clover content in grazed swards. The expected theoretical efficiencies were not observed due to the method of selection of quadrats and the nature of the distribution of herbage mass. Nevertheless there should be worthwhile improvement in precision over random sampling, provided that the quadrats within a set are as well spaced as possible, allowing, if necessary, for visual comparison.

New ranked set sampling for estimating the population mean and variance

“…[4] , Y [9] ) + Cov ( Y [4] , Y [16] ) + Cov ( Y [4] , Y [21] ) + Cov ( Y [4] , Y [28] ) + Cov ( Y [4] , Y [33] ) + Cov ( Y [9] , Y [16] ) + Cov ( Y [9] , Y [21] ) + Cov ( Y [9] , Y [28] ) + Cov ( Y [9] , Y [33] ) + Cov ( Y [16] , Y [21] ) …”

“…For k = 6, we have to select 36 units from the population and then measure only 6 units of them to be a neoteric ranked set sample which are Y [4] , Y [9] , Y [16] , Y [21] , Y [28] , Y [33] .The NRSS mean estimator can be obtained as…”

“…While bringing the sample units to the laboratory and use actual laboratory techniques to measure its chemical parameters is expensive. For similar applications of RSS in environmental studies, we refer to Cobby et al [9], Halls and Dell [12], Martin et al [14], and Ozturk et al [17]. The standard ranked set sampling design can be described as follows: I.…”

Rank Set Sampling in Improving the Estimates of Simple Regression Model

“…The layout of RSS is given in Table-2. The relative efficiency of RSS with SRS and SYS along with R 2 and Adj R 2 are given the Table-3. The performance of RSS with SRS and SYS is also judged with the help of validation technique i.e.…”

“…RSS has been used to estimate shrub phytomass, Martin et al, (1980), mass herbage in a paddock, Cobby et al, (1985) in order to achieve observational economy and increased precision over simple random sampling (SRS). Gilbert (1995) recommended it for environmental research quieries such as estimating plutonium soil concentrations and Nussbaum and Sinha (1997) discussed the problem of quality testing reformulated gasoline with reference to RSS.…”