reaalijoukossa

Reaalijoukossa is the inessive form of the Finnish noun reaali-Joukko, a term used primarily in statistics and mathematics to refer to the real population or base set under consideration. In this usage, the reaali-joukko represents the complete group of elements about which inferences are made or properties are described. In Finnish statistical writing, it is commonly used synonymously with perusjoukko or populaatio, though terminology can vary by textbook or discipline.

In practice, the reaali-joukko contrasts with the sample (otanta), which is a subset drawn from the real population for the purpose of analysis. Analyses aim to estimate population parameters (such as the mean or variance) from data collected within the reaali-joukko or from a sample drawn from it. When a census is conducted, the otanta equals the reaali-joukko, since the entire population is observed.

Terminology notes: while reaali-joukko is a general concept in statistics and mathematics, its precise label may differ across sources. Some texts prefer perusjoukko or populaatio to describe the same idea of the complete set, while reaali-joukko emphasizes the real or actual set of interest in a given context. The form reaali-joukossa specifically denotes “in the real population” and appears in sentences describing the location or scope of the population in question.

See also: perusjoukko, populaatio, otanta, tilastotiede, matemaattinen joukko.