A peer interviewer is a person who has direct experience of the topic being researched and carries out interviews with their peers, that is people with a similar experience who are participants in the research project. Involving peer interviewers can improve the quality of the interview data and the experience of the interviewees. Interviewees may be more relaxed and feel they can be more open and honest when interviewed by another service user.

Peer interviewers may not only be involved in the data collection, but can also be involved in developing interview schedules and data analysis. Being involved at multiple stages increases their influence over the research.

When selecting suitable peer interviewers, remember that just having one characteristic in common, for example being a young person or a cancer patient, does not necessarily mean that people will have other characteristics or experiences in common. Depending on the nature of your project and the line of questioning, it may be helpful to match interviewees and interviewers on additional characteristics, such as gender, ethnicity or their use of a particular service and so on.