Cluster or Multi-stage Sampling is the technique for producing a new toothpaste because,
Cluster sampling is a frequently-used, and usually more practical, random sampling method. It is particularly useful in situations for which no list of the elements within a population is available and therefore cannot be selected directly. As this form of sampling is conducted by randomly selecting subgroups of the population, possibly in several stages, it should produce results equivalent to a simple random sample.
The sample is generally done by first sampling at the higher level(s) e.g. Randomly sampled countries, then sampling from subsequent levels in turn e.g. Within the selected countries sample counties, then within these postcodes, the within these households, until the final stage is reached, at which point the sampling is done in a simple random manner e.g. Sampling people within the selected households. The 'levels' in question are defined by subgroups into which it is appropriate to subdivide your population.
Cluster samples are generally used if:
- No list of the population exists.
- Well-defined clusters, which will often be geographic areas exist.
- A reasonable estimate of the number of elements in each level of clustering can be made.
- Often the total sample size must be fairly large to enable cluster sampling to be used effectively.
Pankaj Kumar Singh
New Delhi
Cluster sampling is a frequently-used, and usually more practical, random sampling method. It is particularly useful in situations for which no list of the elements within a population is available and therefore cannot be selected directly. As this form of sampling is conducted by randomly selecting subgroups of the population, possibly in several stages, it should produce results equivalent to a simple random sample.
The sample is generally done by first sampling at the higher level(s) e.g. Randomly sampled countries, then sampling from subsequent levels in turn e.g. Within the selected countries sample counties, then within these postcodes, the within these households, until the final stage is reached, at which point the sampling is done in a simple random manner e.g. Sampling people within the selected households. The 'levels' in question are defined by subgroups into which it is appropriate to subdivide your population.
Cluster samples are generally used if:
- No list of the population exists.
- Well-defined clusters, which will often be geographic areas exist.
- A reasonable estimate of the number of elements in each level of clustering can be made.
- Often the total sample size must be fairly large to enable cluster sampling to be used effectively.
Pankaj Kumar Singh
New Delhi