Glossary term
Sample Survey: Meaning and Definition
Reviewed and approved by Dr. Anamika ShrivastavaPublished Last updated
A sample survey collects information from a selected part of a population and uses it to draw conclusions about the whole. If the sample is representative, results are reliable, faster and cheaper than a census. Selection may be random, giving every unit a known chance, or non-random.
In more detail
A sample survey works when the sample represents the whole. Random selection gives every unit a known chance of being chosen, so the error can be estimated; stratified sampling ensures each group is included. Large national surveys use multi-stage designs, choosing villages or blocks first and households next.
Example
To estimate average monthly income of 1,000 shopkeepers, a surveyor picks 100 at random from a list and asks each of them, instead of visiting all 1,000.
Key points
- A representative sample mirrors the population.
- Random selection lets the error be estimated.
- Results carry a sampling error.
Common mistake
Treating any convenient group as a sample. Convenience samples can be biased.
Related terms
Where it is explained
This term is explained in Class 11 Statistics Chapter 2: Collection of Data.