In order to recruit people who can answer your research questions, you need to be familiar with a range of recruitment strategies and terms. First, let's look at sampling. It's tempting to recruit people for interviews that you already know or who are easy to get hold of. It's also tempting to include people who sign up for interviews or out of free will or interest. This may all be good and well. But before you start to invite people, it's important to define your population, what that population is, and the characteristics that they should have. From a population, you invite a sample which can shed as much light as possible on your topic. Convenient sample. It's rather common to use a convenience sample, A group of people that are easy to reach. It could be students or colleagues or people that you know from other settings. All the people who are interested in your research network, it's easy to get hold of. Snowball sampling is when participants suggest new participants within their network. This might happen when they, for instance, have the same diseases and they're in the same age group. They are in a larger network of people, like say, a Facebook group. But where you as a researcher easily can recruit more patients who have knowledge about a topic or similar diseases. An advantage with snowball sampling is that you get people with great insight in your topic. However, be aware that you might get less variation in the answers than if you recruit people from a whole larger population. Other times we make purposive selection of interviewees to attract a sample that's really as tailored as possible. This we do to get a more in-depth understanding of the topic. We do normally not use statistics to calculate a number of participants when we do qualitative study. We can, however learn something from statistics, a non-probability sample is where you self choose informants based on your own good judgment as a researcher, but even for a small sample of participants, let's say, 10 people. It's worthwhile to consider how you can get the widest possible variety amongst those interviewees. This is something we call the stratified sample, and it means that the participants are selected from subgroups within a larger population to make sure that they represent different experiences or opinions, or different gender or ages, or even socio-economic backgrounds, as an example. It could also be that they take certain medicines and have certain diseases that you want to explore how their perceptions of medicines' use. This type of sampling, stratified sampling, makes sure you don't end up with only men, or only retired people, or only people who are not in a full-time job because people who work might not have time for you. Moving on. How do you recruit people? We've all been stopped on the street sometimes or someone calls you or sends you an e-mail and asks you for an interview or to respond to a questionnaire or a survey. This could be on consumer habits or it could be on your services, how you were satisfied with the hotel you stayed in. But it could also be deeper in like political or societal issues. So let me ask you, what did you answer? How did you respond the last time you received such a request to attend a survey? Doesn't matter what you really said, if you agreed or not, but our response to accepting or declining is often based on our interests and is also based on our knowledge. For instance, if I'm asked to take part in a survey, where I have very little knowledge, say cars, I might be less inclined to say yes than if something I know a lot about or have strong opinions about. When you and I decide to take part or not, it can result in what we call a response bias. The sample you as an interviewer end up with could be an under-representation of certain people or certain opinions, and it could bean over- representation of the same thing. In qualitative research, we are not so concerned about generalizing in the same way as in a larger quantitative study. However, when you recruit people for your qualitative study, just be aware that this answer from people to take part or not influences your sample and therefore also influences your results. Moving on. My students often ask me, how many people on the guide should we recruit for the interviews? When do we have enough informants? Is it three? Is it five? Is it 10? Is it 20? When do you know to stop? A common approach to this in qualitative study on recruiting new people is when you reach a certain level of saturation. Saturation means that when you get very little new information by adding new informants. If you're new to the interview method, it might be difficult to know when you have reached this point of saturation. But a good advice is to do two or three interviews and then analyze and look at the answers you have gotten from them and see, does this answer my questions? If not, you just continue to do more interviews. That was it for now about the different recruitment strategies, what you should consider when recruiting people for interviews. I hope this has inspired you to think about how you can get the most depth and the most width in your sample, and to get a sample of people that really can answer your research questions. Thank you for listening.
