Question

Define the following terms and provide an example for each:

1. Population

2. Sample frame

3. Sample

4. Representative sample

Answer 1

(1)

Population is the complete set of data which is to be examined from a particular point of view, or working upon which some claim has to be tested. Population forms the basis of an experiment. All probabilistic experiments are conduced to study some parameter associated with the population.

(2)

Sampling frame is that subset of the population which can actually be sampled for the experimentation procedure. In some case it is possible to select all the items in the population individually, while in some cases it is not possible. So in the latter case we establish a sample frame, which denotes that portion of the population which can be feasibly sampled.

(3)

Sample is a small set of data which is extracted from the population for the study purpose, because it is not practically possible to apply the same set of conditions to each and every member of the population, if the population size is too large. So to deal with it, a small sample is extracted from that population itself and experiments are conducted on it.

(4)

A representative sample is a sample which is a very accurate manisfestation of the population, which means that all the parameters associated with the population are accuarately present in the sample as well. So a representative sample is said to be a true reflection of the population.