Are units observed at every stage of multistage sampling?

Question

Is it true that units are observed at every stage of multistage sampling?

Answer choices

1. No.
2. Yes.

Explanation

At intermediate stages of multistage sampling, larger units are selected, such as geographic areas, organisations, or households. These provide sampling units for the next stage.

The actual observation units are surveyed at the final stage. Selection at every stage therefore does not mean that the ultimate units are observed at every stage.