What are the main sampling design approaches?As we mentioned earlier, sampling design is about deciding who you’re going to collect your data from (i.e. your sample). There are many sample options, but the two main categories of sampling design are probability sampling and non-probability sampling.
Probability sampling means that you use a completely random sample from the group of people you’re interested in (this group is called the “population”). By using a completely random sample, the results of your study will be generalisable to the entire population. In other words, you can expect the same results across the entire group, without having to collect data from the entire group (which is often not possible for large groups).
Non-probability sampling, on the other hand, doesn’t use a random sample. For example, it might involve using a convenience sample, which means you’d interview or survey people that you have access to (perhaps your friends, family or work colleagues), rather than a truly random sample (which might be difficult to achieve due to resource constraints). With non-probability sampling, the results are typically not generalisable.
Source:
https://gradcoach.com/what-is-research-methodology/
