As this lesson you’ll able to know learn complete about sample in statistics so continue…..
Literal meaning Sample in statistics – small representative part or quantity or specimen. Sample is a small part of population. It is a finite subset of population which is drawn for the purpose of investigation. In other words, it is a fraction of population which represents all the property of population. The number of objects included in the sample is known as sample size. It is generally denoted by ‘n’.
What are two Type of sample in statistics?
The two types of sampling are: Random sample and Non-random sample are discuss below:
If the sample units are selected randomly (by chance) from the given population, then the sample is called a random sample. More precisely, random samples are selected by using simple random sampling technique. Random samples are not selected on basis of
investigator’s judgment, view, choice. Random sample may be the true representative.
Non Random Sample
If the sample units are not selected at random from the given population, then the sample is called non random sample. No any chance is associated with the selection of nonrandom sample. And are selected on the basis of investigator’s view, judgment, choice. Non random samples may not be true representative.
Characteristics of a good Sample:
- A sample should be representative.
- The size of the sample should be adequate.
- Sample should be free from prejudice and biases.
- It should have the conformity to the objectives of the study.
- It should be based on practical experiences etc.
Census survey and sample survey in statistics
Census survey is the complete enumeration of population in which each and every units of population is taken to study. Population census, Agricultural census, Industrial census etc. are some example of censuses.
Merits: census survey
- Deep study is possible.
- High level of accuracy.
- Useful in heterogeneity.
- Necessary in some situation.
- Suitable for small population
Demerits: census survey
- Time consuming.
- Inappropriate in case of destructive items
- Not possible in every situation.
Sample survey: The enumeration of selected sample units is known as sample survey. Food survey, health survey, market survey etc. are some example of sampling survey.
Merits: Sample survey:
- Complete inspection is possible.
- Less time consuming and less expensive.
- Appropriate for social and economic issues related research.
- Mandatory in some cases.
Demerits Sample survey
- Possibility of inaccurate result.
- Sample may not be representative.
- In appropriate in high level accuracy.
- Both sampling and non-sampling errors may occur