Recruiting the Impossible

Using Guerilla Recruiting to find hard-to-reach participants

Where is the best place to talk to busy, stressed travelers? What is the ideal environment to talk to tourists on a strict schedule? Sometimes it seems like the people we need to talk to are out of reach. A tourist wouldn’t want to take part in a user interview while on their vacation. Travelers running through the airport or the train station are way too busy to entertain your questions. So, how can we find these hard to recruit participants?

Sure, you can bring people into an interview room and ask them to describe their last vacation, or simulate some kind of airport scenario, but you are losing valuable information by not being immersed directly in the context. Unconscious reactions and behaviors to random external stimuli are very pure reflections of peoples’ underlying motivations and attitudes, which often get covered up or exaggerated in a “lab” setting.

More than that, people are not great at recalling information, so telling them to speak from a specific memory could generate unreliable insights. Simulating a scenario can be useful at times, but in the end, the insights gained from a mimicked environment will always reflect that inauthenticity.

As researchers, it is our responsibility to portray the people we speak to, in the most accurate way possible. That means we have to adapt to our participants’ ways rather than try to entangle them into our worlds. The people we want to talk to are everywhere, and it’s time we start adapting to their contexts.


For one research project, we wanted to paint a comprehensive picture of what mobility in Hamburg looks like. We decided that in order to make this happen, we would need to speak to people who move around Hamburg every day, as well as people who are unfamiliar with the city at varying levels. We spoke to a lot of recruiting agencies, asking if this would be possible, and they all said the same thing: No. They told us that it would be impossible to recruit tourists or people who don’t know the city very well because these people were simply too hard to catch. Besides, who would want to take part in a research study during their holiday?

We decided we would have to take matters into our own hands and find these people through guerilla recruiting. This method plays out in a public setting by asking random people to speak with you. Is it unconventional? Maybe. Does it work? Depends. Guerilla recruiting can be seen as an unstructured, inconsistent method, because you are, after all, talking to random people on the street who might have nothing to do with your target audience. But that’s the beauty of it. Not only is guerilla recruiting time and cost-effective, but it also brings diversity to your set of participants which you might not have considered before.

From our experience working at a digital agency in Germany, participants of user research for widespread digital products are quite “average” people who meet a very narrow set of demographics. This usually includes working-class people who are generally tech-savvy, within the ages of 20–65, live in an apartment or a house and have a phone. Nothing out of the ordinary. Sure, you can get a bit more specific in your criteria, such as recruiting people who are in the process of buying a car, or who have a certain medical health condition, but to a certain extent, the participant pool remains homogenous. This one-dimensional recruiting leads to a bland pool of insights with disregard for people living in or with some kind of extreme that you haven’t considered.

Guerilla research partially removes that filter as the whole world is your oyster. Once you are in public, you can’t screen people in the way you normally would for a user test. Sure, you can look at their appearance and actions, but you don’t really know anything about them. This leads to insights that paint a comprehensive picture of the topic rather than focusing on one tiny moment wrapped and protected in a bubble of “safe” recruitment.


To find these “unlikely” participants for our mobility study, we first went to the main train station and stood on the platform of the train going to the airport. Realizing that the train came every 10 minutes, we knew we could engage in micro interviews during this time. Every time a train left, we searched for people who had already come for the next train, and since they had to wait for 10 minutes, they were usually more than willing to engage in conversation with us. Through this recruitment process, we ended up speaking to a lot of tourists from many different backgrounds. This enabled us to get diverse perspectives on how people in Hamburg travel back and forth from the airport.

Another tactic we used to find tourists, was to go to the main sites in the city center. We stood in a busy area and looked for people who appeared that they might not be from Hamburg. In this attempt to screen, we looked for people holding maps, walking slowly, observing monuments, etc. We, again, ended up speaking to a variety of people. Some ended up being tourists and some weren’t, but they all provided personal insights to help piece together the story of mobility in Hamburg.

In this setting, people were a bit more hesitant to speak to us. This is understandable since people are used to solicitors standing around the city to sell stuff or to collect donations. Most people get annoyed by this type of interaction, so we tried a few different openers to catch people. We also brought an interactive “conversation object” with us to ease people into a conversation.


Given that we didn’t have a lot of time and money to find tourists for this study, the guerilla recruiting approach ended up working really well. Just because it’s quick, doesn’t mean it’s dirty. This method works wonders when there is not enough time or budget, making it an excellent way of conducting research in agile frameworks where time is limited. Guerilla recruitment also allows you to potentially diversify your set of participants with minimal effort since there is no real opportunity to screen. Moreover, you are able to observe people in their natural environment, which leads to more authentic behaviors and interactions with your topic of exploration. And because you are catching people off-guard, you can get enthusiastic, and less rehearsed responses, which lead to more creative ideas and findings.


Of course, we also encountered some setbacks. There are some days where it seems that people are unwilling to speak with you. You have to overcome your fear of approaching strangers, and hearing the word “no”. You have to let go of a clean, structured research plan, and you can’t reach a significant level of depth during these short interventions. You can’t confront people about super-sensitive topics like money or health and you can’t guarantee to find a specific set of participants if needed. Like any other method, there are weaknesses and limitations to what can be achieved with guerilla research, but it’s generally something that can be balanced out by another method.


Guerilla research is just one of the methods we used in our overall study of mobility. In addition, we conducted interviews, did diary studies, and shadowed people on their everyday journeys. This cross-pollination of methods allowed us to explore the topic from multiple angles, as well as balance the strengths and weaknesses of the respective methods. In the end, alongside other methods, guerilla recruiting provided a quick and cost-effective way for us to get contextual insights that contributed to painting a larger, diversified picture of mobility in Hamburg.