Sampling Method

When attending statistics class, students are often need to learn to design and conduct a survey on a specified group of respondents. When the respondents census consist of too many people, it is often wiser to conduct the survey on a sample. Below are some of the sampling method one can use.

Different types of sampling method

Simple random sampling

In this method, all possible sample size of n are equally likely to be selected. Example of simple random sampling method.

Systematic sampling

To use this method, one has to first arrange the population in certain order (eg. alphabetically), then choose every kth member from the list after each sampling point.

Example of how systematic sampling method is performed

If systematic sampling method is to be apply to choose a sample of 100 samples out of the population size of 5000. One has first to determine an appropriate interval by taking 5000 divide by 100 which is equal to 50. Using a random starting point (eg. 15), selected the 15th entry of the population as the first sample, then 65, 115, etc.

More about systematic random sampling method.

Stratified sampling

This method will first create sub-groups population based on certain characteristics (eg. occupation), then one can perform random sampling to select approriate size of sample from each stratum.

Cluster sampling

Population are allocated into sub-groups called cluster.