השוואת שיטות

	דגימת אשכולות רב-שכבתית	דגימת אשכולות פרופורציונלית – הסתברות פרופורציונלית לגודל
תחום	מתודולוגיית סקרים	מתודולוגיית סקרים
משפחה	Process / pipeline	Process / pipeline
שנת המקור	1950s-1970s (cluster sampling); multilevel extension formalized 1980s-1990s	1950s–1960s
הוגה השיטה	W. G. Cochran (cluster sampling foundations); extended into multilevel contexts by survey methodologists	Formalized by William G. Cochran and Leslie Kish
סוג	Probability sampling design	Probability sampling design
מקור מכונן	Cochran, W. G. (1977). Sampling Techniques (3rd ed.). Wiley. ISBN: 978-0471162407	Cochran, W. G. (1977). Sampling Techniques (3rd ed.). John Wiley & Sons. ISBN: 978-0471162407
כינויים	hierarchical cluster sampling, nested cluster sampling, multi-stage cluster sampling, clustered multilevel sampling	PPS cluster sampling, proportional-to-size cluster sampling, size-proportional cluster sampling, probability proportional to size sampling
קשורות	6	6
תקציר	Multi-level cluster sampling is a probability sampling design for hierarchically structured populations — such as students nested within classrooms within schools within districts. Clusters are randomly selected at each level of the hierarchy before individual units are sampled within the final-level clusters. The design mirrors the natural nesting of real-world populations and enables efficient large-scale data collection while supporting multilevel statistical analysis.	Proportional cluster sampling selects naturally occurring groups (clusters) from a population with probability proportional to each cluster's size, so that larger clusters have a higher chance of selection while every individual element retains an equal overall inclusion probability. This design efficiently handles large, geographically dispersed populations and is the backbone of national health, education, and social surveys worldwide.