BACKGROUND The return of chloroquine-sensitive Plasmodium falciparum to the limited area of Blantyre, Malawi, has been well demonstrated in several studies. METHODS To characterize chloroquine susceptibility over a wide geographic area, infants and children aged 6-59 months were selected using 2-stage cluster sampling in 8 Malawian districts. Pyrosequencing of the pfcrt gene codon 76 region w...

one of recent developments in modern societies is the evolution in the structure of power division in the family and changes in reciprocal actions between wife and husband. this research aims to study the factors affecting distribution of power in the family by using the theories of: social capital, valuable resources, and sociability of gender. the data has been collected through survey method...

Cluster sampling has recently been used to estimate the mortality in various conflicts around the world. The Burnham et al. (2006) study on Iraq employs a new variant of this cluster sampling methodology. The stated methodology of Burnham et al. (2006) is to (1) select a random main street, (2) choose a random cross street to this main street, and (3) select a random household on the cross stre...

A multi-stage cluster sampling is proposed for quantifying and monitoring plant species richness at multiple spatial grains over large spatial extents. An unbiased estimator of average species richness at different grains and a conservative estimator of its sampling variance are obtained in a complete design-based framework, i.e., avoiding any assumption about the ecological community under stu...

Scott and Smith (1969) develop estimators for linear functions from a two stage cluster sample, with their discussion repeated in many places. This discussion was reviewed in c01ed13.doc. It is note-worthy that Scott and Smith allow expressions for the variance to depend on the cluster. A similar development is given by Vallient et al.. We repeated the derivation of Vallient et al using the fin...

BACKGROUND Traditional Lot Quality Assurance Sampling (LQAS) designs assume observations are collected using simple random sampling. Alternatively, randomly sampling clusters of observations and then individuals within clusters reduces costs but decreases the precision of the classifications. In this paper, we develop a general framework for designing the cluster(C)-LQAS system and illustrate t...

In adaptive cluster sampling, first proposed by Thompson (1990, 1992) and studied in detail by Thompson and Seber (1996), an initial sample of units is selected and, whenever the value of the variable of interest satisfies a specified condition, neighbouring units are added to the sample. The neighbourhood of a unit may be defined by spatial proximity or, in the case of human population, by soc...