Definition

Noun: 1. A sampling technique where the population is divided into distinct subgroups (strata), and random samples are taken from each subgroup in proportion to its size in the overall population. This method ensures that each stratum is adequately represented in the final sample, improving the accuracy and representativeness of the results compared to simple random sampling.

Usage

• Proportional sampling is used in statistics, market research, and social sciences to obtain a sample that accurately reflects the composition of the entire population.
• It is often contrasted with disproportional or stratified sampling where the sample sizes from each stratum are not proportional to the stratum's population size.

Examples

• To ensure all age groups were fairly represented in the health survey, the researchers used proportional sampling based on census data.
• The study's validity was strengthened by employing proportional sampling, which guaranteed that both urban and rural households were included according to their actual distribution in the country.

Advanced Usage

• "Stratified proportional sampling": A more precise term sometimes used to emphasize that the sampling is both stratified (divided into strata) and proportional.
  • The pollster explained that their stratified proportional sampling method involved creating strata for each income bracket.

Variants and Related Words

• Stratified sampling (n): The broader category of sampling that involves dividing a population into strata. Proportional sampling is a specific type of stratified sampling.
• Stratum (n): A subgroup or layer within a population that shares a common characteristic (e.g., age range, geographic location, income level).
• Disproportional sampling (n): A stratified sampling technique where the sample sizes from different strata are not proportional to their population sizes, often used to oversample a small but important subgroup.

Synonyms

• Stratified random sampling (with proportional allocation): A more technical synonym.
• Quota sampling (with random selection within quotas): A related, though not identical, method in survey research.

Related Phrases

• "To draw a proportional sample": To select a sample using the proportional sampling method.
  • It was crucial to draw a proportional sample from each of the five regional strata.

Noun

1. the population is divided into subpopulations (strata) and random samples are taken of each stratum