Recruiting Research Participants

All recruitment efforts must be underpinned by the principle of voluntary participation. Great care needs to be taken not to create conditions under which potential participants feel pressure to join in the research (National Statement 2.2.9), keeping in mind that people may feel pressure to participate even if that has not been the intention of the researcher.

In your ethics application, it is important that you describe recruitment plans and processes in detail: who, how many, and how people will be recruited, the reasons behind these plans, and what you will do if initial efforts don’t work as well as you had hoped. Be as realistic as possible when thinking about who might be willing and able to participate in your research. Vague, overly optimistic descriptions about recruitment will generally not be accepted at face value.

Who to recruit

“Who” is recruited to participate in your research depends on your research question. Think carefully about your target participant group. Inclusion and exclusion criteria and the reasons for each must be clearly identified in the protocol and in your recruitment materials, in a respectful and inclusive way (e.g. providing non-binary gender options). It helps to be realistic about whether people from your target participant group will be happy to join your research, so you can adjust your target group and/or recruitment plans accordingly.

How many to recruit

For quantitative studies, you may have calculated a required sample size (e.g. to achieve a desired level of power or precision in your research outcomes when making statistical inferences). For qualitative research, where the objective may not be to generalise findings from a sample to a population (e.g., ethnographic studies) other reasons for the number of participants proposed and the method of recruiting participants (sampling) may be used.

How/how not to recruit

• Snowball sampling. Researchers need to be aware that such an approach may create conditions for potential participants whereby they feel pressure to join the research because they have been referred by a friend or colleague. It is particularly important in such cases to ensure that the principle of voluntary participation is stressed in information given to potential participants. It is also important in this vein to explain to potential participants that research typically will not benefit them directly. Even though this advice may seem to limit the prospect that they will join, it is essential to the ethical conduct of research.
• When recruiting does not go as planned. If recruitment does not proceed as planned, you may need to submit a variation to expand recruitment efforts, perhaps by using online platforms like Facebook, or by adding an incentive.
• Incentives/remuneration. Sometimes, a small incentive (e.g., a gift card) can encourage people to consider participating in your research, and is also an appropriate gesture of thanks for the participants’ time and effort. However, the researcher must ensure that this incentive is not coercive. See the section on remuneration for participants.