Vertaile menetelmiä

	Systemaattinen otanta verkossa	Proportionaalinen systemaattinen otanta
Tieteenala	Kyselytutkimuksen metodologia	Kyselytutkimuksen metodologia
Menetelmäperhe	Process / pipeline	Process / pipeline
Syntyvuosi	Late 1990s–2000s (web survey era)	Mid-20th century (formalized ~1950s–1970s)
Kehittäjä	Adapted from classical systematic sampling (Madow & Madow, 1944) for web survey contexts	Codified in classical survey sampling theory; see Cochran (1977)
Tyyppi	Probability sampling design	Probability sampling design
Alkuperäislähde	Couper, M. P. (2008). Designing Effective Web Surveys. Cambridge University Press. ISBN: 978-0521713528	Cochran, W. G. (1977). Sampling Techniques (3rd ed.). Wiley. ISBN: 978-0471162407
Rinnakkaisnimet	web systematic sampling, digital systematic sampling, interval sampling online, e-survey systematic sampling	proportional 1-in-k sampling, equal-probability systematic sampling, proportionate systematic selection, PPS systematic sampling
Liittyvät	4	6
Tiivistelmä	Online systematic sampling applies the classical every-k-th-element rule to digital survey contexts — selecting respondents from a web panel, membership database, or visitor stream at a fixed interval. It combines the operational simplicity of systematic sampling with the reach and speed of online data collection, producing a roughly representative sample without requiring complex randomisation infrastructure.	Proportional systematic sampling combines systematic (every k-th element) selection with proportional allocation across subgroups, ensuring that each stratum contributes sample units in proportion to its share of the total population. The result is an equal-probability design that is administratively simple, spreads the sample evenly across an ordered frame, and eliminates the need for post-hoc weighting when strata are sampled at a uniform rate.