Now that we’ve selected guerrilla testing as an appropriate method for our research, how do we make sure we get the best results?

When dealing with the tradeoffs of time and rigour, it’s important to be as prepared as possible on the day. Here are some of our rules of thumb for before, during, and after test day.


A refined and rehearsed discussion guide adds structure to your tests. We have found value in front-loading our most important questions and leaving the ‘nice-to-know’ toward the end. Doing a dry-run with colleagues will help to trim down the script, weed out ambiguous questions and flush out prototype gremlins.

The day before, it’s worth checking the weather and dressing to suit. Nothing’s going to shut down our test day quicker than hypothermia or heat stroke. Striking a balance between smart and casual clothes helps with first impressions. If we’re targeting a particular audience or visiting a location with a specific dress code, go with the flow and try to blend in. Our overall aim is to instil a sense of trust and credibility.

A day of research fieldwork can be long and tiring. It’s important to be a supportive wing-person and keep spirits high so you can go that extra mile if you need to. Our research kit bag is like another team member. It has our back when the going gets tough. Alongside our essentials, we make sure to have a few extras to brighten the mood and revitalise the team. Here are a few things we wouldn’t leave the office without:

  • Spare battery, charge block and cables. Don’t let the tech let us down.
  • Painkillers, chewing gum and lip balm. Because we’re worth it!
  • Go-to snacks of choice. Everyone has their favourite so make sure you know your team’s weakness, savoury or sweet.
  • Screen wipes and antibacterial gel. Our participants won’t want to handle a grubby looking device and neither will we.
Clearleft research kit bag guerilla testing
Contents of guerrilla testing kit bag.


Choosing where we conduct our research is an intentional decision based on prior thinking. Online maps help us to explore areas of interest and potential places our audiences will be congregating. Maps also help us choose a place to set up base for the day. Coffee shops are a firm favourite for guerrilla testing. If you do intend to use a coffee shop, it‘s worth calling ahead to get permission to run sessions on the premises. The prospect of a continuous flow of customers can be appealing to businesses. They might even have a dedicated room you can use for extra privacy.

The ideal location is somewhere with a lot of footfall and not much flow. We’ve had success in public parks, gardens, and museum forecourts. These places are quiet and intimate. We’ve had less success in train and bus stations. Although a high volume of people congregate there, they tend not to give you their full attention and they might have to leave suddenly.

Approaching people out in the field can be awkward for both the researcher and the participant. Be respectful of their context and show genuine interest in talking to them. The reality is that they may be on a lunch break, on the way to an important engagement or just want some headspace. Choosing who to approach will require all of our researcher ‘spidey sense’. There are a number of visual cues that help us decide if someone is likely to give us their time. Here a few examples:

  • Body language - If people are closed-in on themselves or avoiding eye contact, chances are they don’t want to be disturbed.
  • Activity - Avoid people who are eating, performing a complex task, or engaged in a conversation. You may want to approach people after they have completed a task if it relates to your research but use your common sense.
  • Groups - Approaching a group of people can increase your success rate but conditions apply; match the ratio of the group size to researcher (1:1), split up for efficiency, and above all stay safe.

When someone does give you their attention, smile, be confident and concise. We find one person approaching is less intimidating than two. Have your partner sitting somewhere within eyeshot with all the test equipment ready. Introduce yourself and give just enough context to inform them without overwhelming them. If they accept, use the time it takes to walk to your partner to ask a few questions and add a bit more context.

The reality is that you will be turned down a lot. This is normal. To flip the perspective on rejection we like to turn it into a game. The rules are simple:

  1. Both researchers alternate in approaching people.
  2. If a researcher is rejected they get a point.
  3. Once you have reached your quota of research sessions, the researcher with the most points wins!

It goes without saying that winning the game is secondary to the success of the research. Still, the game helps to soften the blow of rejection especially for less experienced members of the team.


At the end of the day, discuss what did and didn’t work well. Make a note of which locations proved most successful. Include participant criteria, day of the week and time of day. Recording this information helps us to decide where and when to visit next time. For example, Monday lunchtimes are particularly precious to London city workers after a morning of back-to-back meetings. Then, at 4pm on a Friday, you’ll inadvertently be blocking their beeline to the pub.

Great over good

The advantage of guerrilla testing is that it can be conducted over a short period of time and on a shoe-string budget. Preparation is key for making these brief interactions with our audiences as impactful as they can be. Follow these steps for better research outcomes.

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