stratified sample(redirected from stratified samples)
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Related to stratified samples: Stratified random sampling
stratified samplea SAMPLE which is selected by first stratifying the parent population. The procedure involves dividing the population into strata relevant to the study to be undertaken, e.g. for a study of voting intention, social class and age may be relevant; for a study of attitudes to the benefit system, income level and employment status would be relevant. When the strata have been identified RANDOM SAMPLES are taken from each. As long as these samples are of sizes proportionate to the size of each stratum within the parent population (proportionate stratification), this method allows improved precision, particularly if a sample is being taken from a relatively large population, since it introduces some controlled restrictions on selection. However, disproportionate stratification may be used if a stratum is too small to yield a sufficiently large sample for analysis if the criterion for selection used in other strata is adopted.
Collins Dictionary of Sociology, 3rd ed. © HarperCollins Publishers 2000