In two-stage cluster surveys, the traditional method used in second-stage sampling (in which the first household in a cluster is selected) is time-consuming and may result in biased estimates of the indicator of interest. Firstly, a random direction from the center of the cluster is selected, usually by spinning a pen. The houses along that direction are then counted out to the boundary of the ...

traditional survey methods may cause refusals to respond or untruthful replies when encounter the sensitive questions. the randomized response technique (rrt) is designed to decrease social desirability bias and obtain reliable estimates. this study aimed to apply these new methods on the sensitive questions survey.simmons model was applied in the survey of issues relevant to commercial sex amo...

The lifetime prevalences of DSM-III mental disorders using Korean version of DIS-III are presented. They were studied in 5,100 adults (aged 18 to 65) in household selected by two stage cluster sampling. Comparisons were made between regions, sex and age groups. International comparison with Epidemiologic Catchment Area program was also made.

We present notation that can be used to express a simple model for a nested study. The model is based on the assumption that response has been reported for subjects selected via a two stage cluster sample. At the first stage, a simple random sample of clusters (which we will also refer to as primary sampling units (PSU)) is selected. At the second stage, a simple random sample of subjects (whic...

This study examines the efficiency of EPI cluster sampling in assessing the prevalence of diarrhoea and dysentery. A computer was used to simulate fieldwork carried out by a survey taker. The bias and variance of prevalence estimates obtained using EPI cluster sampling were compared with those obtained using simple random sampling and cluster (stratified random) sampling. Efficiency ratios, cal...

There are two generations of Gibbs sampling methods for semi-parametric models involving the Dirichlet process. The rst generation suuered from a severe drawback; namely that the locations of the clusters, or groups of parameters, could essentially become xed, moving only rarely. Two strategies that have been proposed to create the second generation of Gibbs samplers are integration and appendi...

Evolution of small-vacancy clusters in bcc Fe is simulated using a multiscale approach coupling an atomistic activation-relaxation method for sampling transition-state pathways with environment-dependent reaction coordinate calculations and a kinetic Monte Carlo simulation to reach time scales on the order of ~10⁴ s. Under vacancy-supersaturated condition, di- and trivacancy clusters form and g...

Synthetic populations are used to study methods for adapting Efron’s bootstrap estimation technique to finite population sampling. Of particular interest is the extention of these methods to two-stage cluster sampling. Using simulations based on five artificial populations, two variations of bootstrap estimators and two Taylor series variance estimators for a ratio estimator are compared by mea...