Types of Non-Probability sampling:
- Judgmental sampling
- Convenience sampling
- Quota sampling
- Panel sampling
- Snow ball sampling
@ JuSC QuP
a. Judgmental sampling:
- Also known as purposive sampling
- Sampling only based on researcher knowledge and judgement.
- Enables to select cases that will best answer research questions.
- Done with limited people that have expertise in the area.
b. Convenience sampling:
- Involves selecting haphazardly those cases that are easiest to obtain.
- Eg: Interviewing at random in a shopping Centre for a television program.
- Also called grab or opportunity or accidental or haphazard sampling.
- Most useful for pilot testing.
- Create sample as per ease of access, readiness to be part of sample, availability at a given time slot.
c. Quota sampling:
- Based on pre-set standard.
- Quick method of collecting samples.
- Selection is entirely non-random.
- Interviewers may ask questions to those who look most helpful hence result can be biased.
d. Snow ball sampling:
- Based on chain-referral.
- Sampling can go on and on till researcher is justified with the data to analyze and draw conclusive results.
e. Panel sampling:
- Selecting a group and asking them questions several times over a period.
- Done for nation-wide studies.