We have looked at the different types of sampling methods above and their subtypes. To encapsulate the whole discussion, though, the significant differences between probability sampling methods and non-probability sampling methods are as below:
| Probability Sampling Methods | Non-Probability Sampling Methods | |
| Definition | Probability Sampling is a sampling technique in which samples from a larger population are chosen using a method based on the theory of probability. | Non-probability sampling is a sampling technique in which the researcher selects samples based on the researcher’s subjective judgment rather than random selection. |
| Alternatively Known as | Random sampling method. | Non-random sampling method |
| Population selection | The population is selected randomly. | The population is selected arbitrarily. |
| Nature | The research is conclusive. | The research is exploratory. |
| Sample | Since there is a method for deciding the sample, the population demographics are conclusively represented. | Since the sampling method is arbitrary, the population demographics representation is almost always skewed. |
| Time Taken | Takes longer to conduct since the research design defines the selection parameters before the market research study begins. | This type of sampling method is quick since neither the sample or selection criteria of the sample are undefined. |
| Results | This type of sampling is entirely unbiased and hence the results are unbiased too and conclusive. | This type of sampling is entirely biased and hence the results are biased too, rendering the research speculative. |
| Hypothesis | In probability sampling, there is an underlying hypothesis before the study begins and the objective of this method is to prove the hypothesis. | In non-probability sampling, the hypothesis is derived after conducting the research study. |