Inclusion criteria refers to the characteristics of your population that make them eligible to be in your study. Exclusion criteria refers to specific characteristics of the population that would make them ineligible for your study.

For example: a researcher wishing to study the social media usage habits of single women 18-25, would have the following inclusion criteria:

• female
• age 18-25
• single (defined as not-married/not in a committee long term relationship/not in a committee relationship)

The exclusion criteria for this study would be, of course, anyone who doesn't met that criteria. However a more specific call out might be:

• does not use any social media sites (example: Facebook, Twitter, Pintrest, et cetera)

If the researcher further wanted to research women who have not been married or in long-term committed relationships, further exclusion criteria might be:

• divorced, separate, or has previously been in a long-term committed relationship.

The inclusion/exclusion criteria will be unique to every study. However, it is important for the IRB to understand the targeted population in order to adequately assess potential risks and ensure the study follows the best practises in ethical research.