Collection of Data — Economics STD 11 Commerce — Question

Ans. A sample is that part of universe or population which is selected for the purpose of investigation. A sample must have the following qualities in order to be unbiased and derive right conclusions:

1. Representative: All characteristics of the universe must be represented by the sample. It is possible only when each and every unit of the universe stands equal chance of being selected in the sample.
2. Independence: All the units of a sample must be independent of each other, i.e., one item of a sample should not be dependent upon the other item of the universe.
3. Homogeneity: All selected samples should be homogeneous to each other and not contradictory.
4. Adequacy: The number of items selected as sample should be fairly adequate so that some reliable conclusions are drawn for the universe as a whole.