Once the research question and the research design have been finalised, it is important to select the appropriate sample for the study. The method by which the researcher selects the sample is the ' Sampling Method'. There are essentially two types of sampling methods: 1) probability sampling - based on chance events (such as random numbers, flipping a coin etc.); and 2) non-probability samplin...

the purpose of the present study was to determine gender differences in the language development and skills of first grade students of primary schools in marivan-iran. to do this, 260 first grade students (140 males and 120 females) were chosen by multi stage cluster sampling and stratified random sampling methods among the first grade students in elementary schools in the 2011-2012 academic ye...

Abstract Simple random-sampling resolutions of the raven paradox relevantly diverge from scientific practice. We develop a stratified model, yielding better fit and apparently rehabilitating simple random sampling as legitimate idealization. However, neither accommodates second concern, objection potential bias. third model that crucially invokes causal considerations, novel resolution handles ...

Objective: Happiness, as one of the most important aspects of students’ mental health has a significant influence on their social growth and personality development, and it has always been of interest to the researchers in different fields of psychology. Methods: In this study, the method of correlation was used and the population of study was all students of Farhangiyan U...

Flow-stratified sampling is a new method for sampling water quality constituents such as suspended sediment to estimate loads. As with selection-at-list-time (SALT) and time-stratified sampling, flow-stratified sampling is a statistical method requiring random sampling, and yielding unbiased estimates of load and variance. It can be used to estimate event yields or to estimate mean concentratio...

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...