مقایسهٔ روش‌ها

	پژوهش توصیفی سلسله‌مراتبی	نمونه‌گیری خوشه‌ای
حوزه	طراحی پژوهش	روش‌شناسی پیمایش
خانواده	Process / pipeline	Process / pipeline
سال پیدایش	1980s–1990s (multilevel descriptive formalization)	Early-to-mid 20th century; canonical treatment 1953/1977
پدیدآور	Formalized within survey and educational research traditions; associated with Hox, Raudenbush, Bryk, and Creswell	Formalized by William G. Cochran; roots in early 20th-century U.S. Census Bureau survey practice
نوع	Quantitative observational/descriptive design	Probability sampling design
منبع بنیادین	Hox, J. J. (2010). Multilevel Analysis: Techniques and Applications (2nd ed.). Routledge. ISBN: 978-1848728455	Cochran, W. G. (1977). Sampling Techniques (3rd ed.). Wiley. ISBN: 978-0471162407
نام‌های دیگر	multilevel descriptive design, nested descriptive study, hierarchical survey design, stratified descriptive research	cluster random sampling, area sampling, one-stage cluster sampling
مرتبط	4	5
خلاصه	Hierarchical descriptive research is an observational design that documents the current state of a phenomenon across two or more nested levels — for example, students within classrooms within schools, or employees within teams within organizations. Rather than testing hypotheses or explaining causation, it describes distributions, frequencies, and relationships at each level, making explicit the structured, layered nature of the population being studied.	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.