Сравнение на методи

	Пропорционално просто случайно отбиране	Клъстерно извадково изследване
Област	Методология на проучванията	Методология на проучванията
Семейство	Process / pipeline	Process / pipeline
Година на възникване	Mid-20th century (formalized ~1950s–1970s)	Early-to-mid 20th century; canonical treatment 1953/1977
Създател	William G. Cochran and survey statisticians (classical probability sampling tradition)	Formalized by William G. Cochran; roots in early 20th-century U.S. Census Bureau survey practice
Тип	Probability sampling technique	Probability sampling design
Основополагащ източник	Cochran, W. G. (1977). Sampling Techniques (3rd ed.). John Wiley & Sons. ISBN: 978-0471162407	Cochran, W. G. (1977). Sampling Techniques (3rd ed.). Wiley. ISBN: 978-0471162407
Други названия	proportional SRS, probability-proportional simple random sampling, proportional random sampling	cluster random sampling, area sampling, one-stage cluster sampling
Свързани	6	5
Резюме	Proportional simple random sampling is a probability-based sampling technique in which units are drawn at random from each subgroup of the population in numbers proportional to each subgroup's share of the total population. This ensures the resulting sample mirrors the population's composition across key subgroups, while retaining the randomness and unbiasedness of simple random sampling within each group.	Cluster sampling is a probability sampling technique in which the population is divided into naturally occurring groups (clusters), a random sample of clusters is selected, and all — or a random subset of — members within each selected cluster are studied. It is especially practical when a complete population list is unavailable or when units are geographically dispersed, making individual random selection prohibitively expensive. One-stage cluster sampling surveys every member of selected clusters; two-stage designs add a second random draw within clusters.