Research Methodology
Systematic Sampling
A probability sampling method where researchers select members of the population at a regular interval determined in advance.
What is Systematic Sampling?
Systematic sampling involves choosing a starting point at random from the sampling frame, and then selecting every kth element in the frame (e.g., every 10th person).
Why Systematic Sampling Matters
It is often simpler and faster to implement than simple random sampling, especially when the population is logically ordered or presented as a physical list.
Example
A quality control inspector on an assembly line randomly chooses to start testing at the 3rd item, and then tests every 50th item produced thereafter.
Common Mistakes
- Using it when the sampling frame has a hidden periodic pattern (e.g., every 10th house is a corner house).
- Failing to select the starting point randomly.