Systematic Sampling Method

In this article, let us study what is sampling and the types of sampling.

Preliminary concepts of sampling:

In testing the quality of bulbs produced, by a company it is impossible to test every bub manufactured by a company; it is quite sufficient if a sample is taken for testing and based on this test it is possible to draw conclusion about the population. If each and every item is tested, in some cases it may not be possible to send them to the market. thus, process of sampling is to get information about the population from the sample. To the extent to which we can do this with any accuracy depends on the choice of our sample or samples.

Samples are classified as follows:

non-probability samples

probability samples

Some non -probability samples  are 1. deliberate sampling , 2. Quota sampling 3. Block sampling.

Some probability samples  are1. Random sampling , 2. Stratified sampling , 3. Systematic sampling , 4. Multi stage sampling
What is Systematic Sampling

Systematic sampling with a random beginning is a form of restricted random sampling which is highly useful in surveys concerning enumerable population. In this method, every member of the population is numbered in a serial order and every ith element, starting from any of the first i items is chosen.

My forthcoming post is on  Common Graphs will give you more understanding about Algebra.

Example for Systematic Sampling:

Suppose we require 5% sample of students from a college where there are 2000 students and where everyone is given a departmental number from 1 to 2000, we should first select one number at random from 1 to 20. Suppose the number chosen is 12; then our sample consists of students with departmental numbers 12, 32, 52, 72,..1992

If, however, the students are arranged in groups of 20 such that the first student belongs to the first of 20 specified communities, the second to a second community and so on, then our sample may consist of students of all belonging to the same community and consequently we cannot consider the sample to be random