Cvent Survey

In the past we've explained the different types of probability survey sampling methods, but only mentioned non-probability samples in passing. There are two main advantages to using a non-probability survey method, convenience and cost. Sounds great, but there's a pretty big drawback. Non-probability survey research methods don't allow estimates to how likely survey results represent the actual target population.

Here are two main types of non-probability samples:

Voluntary sample. A voluntary sample is exactly like it sounds, respondents volunteer to complete a survey. As you can imagine, people opting-in to a survey usually have a strong interest in the topic. Their strong interest, of course, could be negative or positive.

Convenience sample. Convenience samples are made up of individuals who are easy to contact. For example, an interviewer needs respondents for a market research study and goes to a local mall because it's close to the interviewer's house. This would be a convenience sample.

Using one of the four types of probably sampling (simple random, systematic, stratified, or cluster) will give you more confidence in the representativeness and accuracy of your survey data, but sometimes there are constraints that limit surveyors to non-probability survey methods.