Definition of sampling
- It is a statistical tool in which a fixed number of observations are taken from a larger population.
- The behaviour or characteristics of the subset is used to estimate the characteristics of the entire population.
Purpose of sampling
- It is to provide information about the statistical information regarding the whole by examining just a few units.
- it reduces the time, effort and cost involved.
- It allows for minimisation of the loss caused in case of any mishap or failure.
- Scientific, observable method of testing a hypothesis.
- There is a greater scope for flexibility and adaptability.
Limitations
- It is not a hundred percent fool-proof method and is prone to errors.
- The sampling might not conform to the standards set.
- The persons administering the experiment might not deal with the sample population effectively.
- It might not be feasible for certain problems that demand a very high level of precision.
Types of Sampling
- Random sampling – it is a kind of sampling in which every item in the population has an equal probability of being picked.
- Block sampling - takes a consecutive series of items within the population to use as the sample.
- Judgement sampling – an auditor’s judgement may be used to select the sample out of the population.
- Systematic sampling – begins at a random sampling point within the population itself and this kind of sampling uses a fixed, periodic interval to select items for a sample.
Application of sampling
- Surveys in most fields are done with the help of sampling. For example, magazines and trade journals utilise surveys to find out what their subscribers are reading.
- It is a useful tool to determine where to channelise one’s advertising and campaigns toward.
- It helps in inferring patterns of behaviour within a specific population in social sciences.
- It is especially useful in medical research when numerous trials have to be conducted.
