Research Methodology
Probability Sampling
A sampling technique in which every member of the population has a known, non-zero chance of being selected.
What is Probability Sampling?
Probability sampling relies on random selection methods to ensure that the sample represents the target population without systematic bias. This allows researchers to use statistical theory to estimate population parameters and calculate margins of error.
Why Probability Sampling Matters
It is essential for making valid statistical inferences from a sample to a broader population, minimizing selection bias.
Example
A researcher studying national voting intentions uses a random digit dialing system to select phone numbers, ensuring every household with a phone has a known chance of selection.
Common Mistakes
- Confusing simple random sampling with other probability methods.
- Assuming a high response rate isn't needed if the initial sample was random.