sampling


Also found in: Dictionary, Thesaurus, Medical, Legal, Encyclopedia, Wikipedia.

sampling

the selection of part of a total population of consumers or products whose behaviour or performance can be analysed, in order to make inferences about the behaviour or performance of the total population, without the difficulty and expense of undertaking a complete census of the whole population.

Samples may be chosen randomly, with every consumer or product in the population having an equal chance of being included. Random samples are most commonly used by firms in QUALITY CONTROL where they are used as a basis for selecting products, components or materials for quality testing.

Alternatively, samples may be chosen by dividing up the total population into a number of distinct sub-groups or strata, then selecting a proportionate number of consumers or products from each sub-group since this is quicker and cheaper than random sampling. In MARKETING RESEARCH and opinion polling, quota sampling is usually employed where interviewers select the particular consumers to be interviewed, choosing the numbers of these consumers in proportion to their occurrence in the total population.

Samples may be:

  1. cross-sectional, where sample observations are collected at a particular point in time, for example data on company sales and the incomes of consumers in the current year, embracing a wide range of different income groups, as a basis for investigating the relationship between sales and income;
  2. longitudinal, where sample observations are collected over a number of time periods, for example data on changes in company sales over a number of years and changes in consumer incomes over the same time periods, as a basis for investigating the relationship between sales and income. See STATISTICAL INFERENCES, QUESTIONNAIRE.
References in periodicals archive ?
Main reasons for inappropriate sample volume in OPD patient can be due to very high patient load, less phlebotomists, along with patient's noncompliance, and difficult sampling. In addition to this sample, collection from OPD is carried out during the fixed hours only.
The American Institute of Certified Public Accountants (AICPA) Auditing Standard Board (ASB) defines audit sampling in AU Section 350-01 as the application of an audit procedure to less than 100 percent of the items within an account balance or class of transactions, for the purpose of evaluating specific characteristics of the entire balance or class (AICPA, 1983).
Haphazard sampling, e.g., taking a few from the top, middle, and bottom of a list, is another form of judgment sampling, as is convenience sampling, where the sample consists of available cases, as when magazines ask readers to fill out a questionnaire.
A probability sampling scheme is one in which every unit in the###Nonprobability sampling is any sampling method where some elements of the population
Before the release of the 2002 Field Directive on the Use of Estimates from Probability Samples, the IRS only sanctioned the use of statistical sampling in specific areas.
In quantitative research, sample size and sampling considerations usually are made with the goal of making statistical generalizations, which involve generalizing findings and inferences from a representative statistical sample to the population from which the sample was drawn.
The most obvious uses of sampling came in the form of dance music in the 1990s, but it is used in many genres of popular music.
Finally, journals could educate their peer reviewers about response rate issues, and attempt to involve a methodologist experienced in survey sampling issues in the review process for papers that report analyses of survey data.
To facilitate accounting for fully deductible M&E, the IRS issued revenue procedure 2004-29, which establishes guidelines for using statistical sampling methods to account for these expenses, whether in art original return, under IRS examination, in litigation or when making a refund claim.
(AES) conducted a series of air sampling as part of the larger project coordinated by Dan Krivit and DKA.
The important distinction in a forensic definition of soil appears in the sampling of earth material, either accidentally or deliberately.