Probability sampling method
There are available most important probability sampling method is given bellow,
Simple random sampling
Systematic sampling
Stratified sampling
Cluster sampling
Simple random sampling
When the population size is very small in this case simple random sampling is very effective. it is a simplest method of sampling for small population.
Simple random sampling method implies that each of the element of population have an equal chance of selecting as a sample. Just consider you are going to select n sample size from a population of N elements. If you do not consider any properties of the sample what you should select, then there have equal chance of each elements of the population of being selected.
Systematic sampling
Systematic sampling method is a method of sampling design that perform by selecting of sample or elements after a certain interval depending on a sampling ratio.
The basic difference and advantage of systematic sampling from the simple random sampling is that it is more easier than the simple random sampling.
Stratified sampling
Stratified sampling method can differentiate fr4om simple random sampling in that way that stratified sampling is more complex than the simple random sampling. But, it is more efficient if accurate implementation happens.
For better understanding of stratified sampling, let us discuss about strata. What means by strata? A strata is a group of elements from a population these ase identical and different from the elements of the other strata of the population.
Cluster sampling
Another most effective sampling method is cluster sampling. The steps of cluster sampling is that dividing the whole population into certain groups and selecting a few groups as a sample these contains different characteristics of elements.