Definition
An important feature of the NSS sampling design is that the total sample of first stage units is drawn in the form of two or more independent and parallel samples, termed as interpenet rating sub-samples. Each sub- sample is drawn by the same sampling scheme and is capable of provid ing valid estimat es of the population parameters. The comparison of sub-sample wise es timates shows the margin of uncertainty associated with the combined sample estimate.
Interpenetrating sub-s amples have been us ed in NSS (i) to obtain valid estimates from each sub-round (season) of the survey r ound, an d (ii) to ensure that Central and State samples for any State/ UT cover independent and equally valid samples of units.