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NationMaster - Encyclopedia: Sampling (statistics) (361 words) |
 | Sampling is that part of statistical practice concerned with the selection of individual observations intended to yield some knowledge about a population of concern, especially for the purposes of statistical inference. |
 | Sample statistic - numerical characteristic of the sample data such as the mean, proportion or variance. |
 | Estimates of the population parameters obtained from a sample are called sample statistics (or sample estimates). |
| Introduction to Sampling (2255 words) |
 | With nonprobability sampling, in contrast, population elements are selected on the basis of their availability (e.g., because they volunteered) or because of the researcher's personal judgment that they are representative. |
 | Probably the most familiar type of probability sample is the simple random sample, for which all elements in the sampling frame have an equal chance of selection, and sampling is done in a single stage with each element selected independently (rather than, for example, in clusters). |
 | Studies with such samples are useful primarily for documenting that a particular characteristic or phenomenon occurs within a given group or, alternatively, demonstrating that not all members of that group manifest a particular trait. |