põhigrupiks

Põhigrupiks is an Estonian term formed with the translative case (-iks) from the noun põhigrupp, meaning base group or core group. The translative case marks designation or a change into a role or state, so põhigrupiks is used to indicate that something is being described as the base group in a larger set, plan, or analysis.

In practice, põhigrupiks appears in academic and applied contexts to designate the main reference or anchor around which data, observations, or activities are organized. It can be used in sociology, statistics, data analysis, education, and project planning. For example: "Uuringus põhigrupiks valiti 50 esinduslikku vastajat" (In the study, 50 representative respondents were chosen as the base group). "Põhigrupiks määrati juhendatud rühm" (The guiding group was designated as the base group). The exact meaning depends on context and may refer to the reference cohort, the anchor for comparison, or the core subset under consideration.

Notes and variations: põhigrupiks is not a universally fixed technical term; different fields might prefer different phrasing such as algrupp or tuumrühm when referring to a base or core set. The expression is primarily a descriptive tool to establish roles within research design, datasets, or organizational planning. See also Estonian grammar on translative case and terms for groupings in research design.