Nest Selection

Cluster selection - see serial selection. Both terms come from the English "cluster sampling". The word "cluster" is used here because in this type of sampling the same respondents are included in several sample groups (in different nests). Selection occurs at random, but sampling units are retained in subsequent surveys. To observe time-invariant variables, special random samples are examined, the repetitions of which are possible over a certain period of time, for example, in the same population groups or in other time periods.