The precision of parameters estimation are determined by the sample size and the sampling design used in a study. Due to such practical constraints as the budget and manpower, most large-scale educational studies would not adopt the simple random sampling design. TIMSS 2007 used a two-stage stratified cluster sampling design. In the first stage, about 150 schools were selected according to some...

BACKGROUND Breast feeding is universally and traditionally practicised in India. Experts advocate breast feeding as the best method of feeding young infants. OBJECTIVE To assess the role of various factors in determining colostrum feeding in block R. S. Pura of district Jammu. MATERIALS AND METHODS A stratified two-stage design with villages as the primary sampling unit and lactating mother...

A distance-based multivariate control chart is a useful tool for ecological monitoring to detect changes in biological community resulting from natural or anthropogenic disturbances at permanent monitoring sites. It is based on a matrix of any distances or dissimilarities among observations obtained from species composition and abundance data, and bootstrapping techniques are used to set upper ...

this descriptive analytical survey was aimed to study the negative impacts of mine exploitations carried out in the rural regions of the tekab township located in iran. the statistical population of the studied areas consisted of all the heads of the rural households in the villages located in the vicinity of the mines in the tekab township (n=2680). according to the cochran formula, a sample s...