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'''Random sampling''' is a [[statistical]] technique which gives everyone in the target group the same opportunity to participate in a [[poll]]. Moree exactly, everyone has a known probability of selectionb. This ensures the '''validity''' of the poll, meaning that the results reflect the target population.

'''Random sampling''' is a [[statistical]] technique in which individuals are randomly selected from the target group (usually a sub-set of the population). More precisely, everyone has a known probability of selection. Generally the aim of this method is to remove [[bias]] in selection of samples, though it may not be suitable for all cases of statistical analysis, depending upon the circumstances.

The '''reliability''' of a poll is a different dimension and refers to the amount of random error still present. The larger the poll, the smaller the random error. (Increasing the size of a poll by X reduces the error by the square root of x. A poll with 4 times as many people  will have half the random error.)

The '''reliability''' of a poll is a different dimension and refers to the amount of random error still present. The larger the poll, the smaller the random error. (Increasing the size of a poll by X reduces the error by the square root of x. A poll with 4 times as many people  will have half the random error.)

In statistical studies, '''random sampling''' refers to the extraction of values (''sampling'') of a designated input [[probability distribution]] for ensuing statistical calculations, such that the relative [[probability]] of extraction is that indicated by the input [[probability density function]] in the case of a continuous distribution or the [[probability mass function]] in the case of a discrete distribution.

In statistical studies, '''random sampling''' refers to the extraction of values (''sampling'') of a designated input [[probability distribution]] for ensuing statistical calculations, such that the relative [[probability]] of extraction is that indicated by the input [[probability density function]] in the case of a continuous distribution or the [[probability mass function]] in the case of a discrete distribution.

==Further reading==

==Further reading==

* Graham Kalton. ''Introduction to Survey Sampling'' (Quantitative Applications in the Social Sciences) (1983) [http://www.amazon.com/Introduction-Sampling-Quantitative-Applications-Sciences/dp/0803921268/ref=sr_1_2?ie=UTF8&s=books&qid=1235831356&sr=1-2 excerpt and text search[

* Graham Kalton. ''Introduction to Survey Sampling'' (Quantitative Applications in the Social Sciences) (1983) [https://www.amazon.com/Introduction-Sampling-Quantitative-Applications-Sciences/dp/0803921268/ref=sr_1_2?ie=UTF8&s=books&qid=1235831356&sr=1-2 excerpt and text search]

 

[[Category:Statistics]]

 

[Category:Statistics]]