nonprobability sampling

statistics

Also known as: judgement sampling

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Last updated

June 29, 2026

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Nonprobability sampling is a method in statistics where the selection of individuals or cases from a population is based on the researcher's judgment rather than on probability theory. Unlike probability sampling, where every element has a known chance of being selected, nonprobability sampling does not allow for the calculation of sampling error or the determination of the likelihood that findings are due to chance.12

A common type of nonprobability sampling is quota sampling, where researchers aim to match the sample's characteristics (like age, gender, or education) to those of the larger population. While this method can be quicker and less expensive than probability sampling, it has drawbacks. It's difficult to ensure representativeness, and the subjective nature of respondent selection can introduce bias. Statisticians generally prefer probability sampling methods because they minimize bias and allow for more reliable inferences about the population.312

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sampling
…alternative to probability sampling is judgment sampling, in which selection is based on the judgment of the researcher and there is an unknown probability of inclusion in the sample for any given case. Probability methods are usually preferred because they avoid selection bias and make it possible to estimate sampling…
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…alternative to probability sampling is judgment sampling, in which selection is based on the judgment of the researcher and there is an unknown probability of inclusion in the sample for any given case. Probability methods are usually preferred because they avoid selection bias and make it possible to estimate sampling…
Read More

sample preparation
Theory
…this category, which is called nonprobabilistic sampling. Such methods can never satisfactorily represent highly heterogeneous material. In contrast, probabilistic sampling methods are techniques in which all constituents of the material have some probability of being included. However, it is only in a correctly designed sampling plan that probabilistic sampling achieves…
Read More
…this category, which is called nonprobabilistic sampling. Such methods can never satisfactorily represent highly heterogeneous material. In contrast, probabilistic sampling methods are techniques in which all constituents of the material have some probability of being included. However, it is only in a correctly designed sampling plan that probabilistic sampling achieves…
Read More

statistics
Sample survey methods
Nonprobability sampling methods, which are based on convenience or judgment rather than on probability, are frequently used for cost and time advantages. However, one should be extremely careful in making inferences from a nonprobability sample; whether or not the sample is representative is dependent on…
Read More
Nonprobability sampling methods, which are based on convenience or judgment rather than on probability, are frequently used for cost and time advantages. However, one should be extremely careful in making inferences from a nonprobability sample; whether or not the sample is representative is dependent on…
Read More