Question

10. Why is a probability sample preferred over a nonprobability sample? Summarize the shortcomings and strengths of nonprobability samples.

Answer 1

To understand, why probability sample is preferred over non-probability sample, we have to know first what is the difference between them.

PROBABILITY SAMPLE : In probability sample method  each and every member of a population has a known and equal chance of being selected. The selection process is random.

NON-PROBABILITY SAMPLE: Whereas is non-probility sample method the selection of group of population for the study is not random. People who are being selected for the study must fall under their preferred criteria to be chosen. For an example they can be near the research center or they must use inetrnet.

REASON WHY PROBABILITY SAMPLE IS PREFERRED OVER NONPROBABILITY SAMPLE

Reason for why probability sample is preferred over non probabbilty is it is easy to conduct. No other easy method exists to extract a research sample from a larger population. There is no need to divide the population into sub-populations or take any steps further and the results are more likely to accurately reflect the entire population.

SHORTCOMINGS AND STRENGHT OF NON-PROBABILITY SAMPLE

The main strenght of a nonprobility sample is that as compared to probility sample, its very time and cost effective. You dont need a very large number of population to work with.

And the shortcomings of the nonprobility sample is that  lack of representation of the entire population and lower level of generalization of research findings.