Compara mètodes

	Campionament per quotes	Mètode d'ajustament per estrats
Camp	Metodologia d'enquestes	Metodologia d'enquestes
Família	Process / pipeline	Process / pipeline
Any d'origen	1930s	1977
Autor original	Developed in market research and opinion polling, notably applied by George Gallup in the 1930s	William G. Cochran
Tipus	Non-probability sampling design	Probability-based survey sampling design
Font seminal	Moser, C. A., & Kalton, G. (1972). Survey Methods in Social Investigation (2nd ed.). Heinemann. ISBN: 978-0435827496	Cochran, W. G. (1977). Sampling Techniques (3rd ed.). Wiley. ISBN: 978-0-471-16240-7
Àlies	quota-controlled sampling, quota selection, non-probability quota sampling	Proportional Stratified Sampling, Optimal Allocation Sampling, Stratum-Based Sampling, Tabakalı Örnekleme
Relacionats	5	2
Resum	Quota sampling is a non-probability technique in which the researcher pre-specifies how many units to recruit from each subgroup (quota cell) defined by one or more control variables such as age, gender, or occupation. Interviewers or data collectors then use their own judgment to find and enroll participants until each cell is filled. The method guarantees the sample mirrors the population on the control variables but does not provide the randomness needed for classical statistical inference.	Stratified sampling is a probability sampling design in which the target population is partitioned into non-overlapping, exhaustive subgroups called strata, and independent probability samples are drawn within each stratum. Formalized by William G. Cochran in Sampling Techniques (1977), the method exploits known population structure to reduce variance and guarantee representativeness of all major subgroups, making it a cornerstone of large-scale survey research and official statistics.