What is guerrilla usability testing?

In this chapter, you'll learn everything you need to know to run guerrilla usability testing, including finding participants, setting up tasks, and more.

If you’re a user experience designer or researcher—or you’ve read the other chapters of this guide—you already understand the value of investing time and money into usability testing. But the common limitations of many design projects may still force you to ask this question:

What if I really don’t have much time for usability testing?

The answer is to take a DIY approach that’s quick and affordable enough to meet the constraints of any deadline: guerrilla usability testing. Not only does it have an exciting-sounding name, but it’s also an effective way to identify usability issues and get valuable insights from people fast.

And while it may not be as rigorous as your normal type of testing, guerrilla testing is far, far more preferable to the alternative—not testing at all.

So let’s take a look at the guerrilla option: what it is, when you should do it, and how to make your guerrilla test a success.

Guerrilla usability testing aims to cut out the time-consuming parts of the user testing process. A designer, researcher, or anyone building a product takes to the streets and finds members of the public to participate in a quickfire, on-the-spot guerrilla usability test.

The term ‘guerrilla’ was first used to describe small groups of armed forces that would launch quick, unexpected strikes on specific targets to make up for their lack of numbers and resources. Since then, it’s become a word to describe any activity performed in an impromptu, unconventional, and effective way.

So if the typical assumptions around usability testing are:

Guerrilla usability testing challenges these assumptions by:

If it sounds simple, that’s because it is. But that doesn’t mean that guerrilla research is too scrappy to provide actionable user feedback. It can actually work just as well as traditional user research methods. Here’s why.

Guerrilla testing works for the simple reason that you're testing with people who haven't seen your design yet. Within your office, these people are probably in short supply. But outside, they’re everywhere—and going directly to them is a massive shortcut compared to arranging for them to come to you. It's a good way to get some quick feedback without investing a lot of resources into traditional user testing.

If your budget or deadline doesn’t allow for traditional usability testing, some guerrilla testing early in the design process can help validate your initial ideas.

And even if you do have the time and money to recruit users for pre-arranged or remote testing, you might want to consider complementing your user research with quick guerrilla tests when you need a quick way to test your solutions with real users.

Guerrilla testing works best as a type of formative testing. This means it’s particularly useful when you need to validate assumptions and identify core usability problems at an early stage of the design process. For instance, if you need some quick data to test the early direction of your design and user interface—but don’t want to go for an established usability testing process, that’s where guerrilla usability testing comes in.

David Simon from UXBooth explains how he used guerrilla usability testing to build a website on a tight deadline:

He also reveals a positive side effect of guerrilla testing early: “Guerrilla usability testing opened our stakeholders’ eyes so that they challenged their own, innate assumptions about the user.”

Designers will be all too familiar with the challenges of getting buy-in from stakeholders to invest time and money into user testing. So if you can get eye-opening results at the prototyping stage with minimal resources, you can prove the value of sharing your product with users without investing too much time and resources into traditional user testing.

However, once you get to the stage where you need more finely-tuned feedback on the overall usability of your designs, it’s better to test a higher number of people in a more standardized way. At this point, it’s best to swap the guerrilla testing for summative testing methods.

By now, we have seen that guerrilla usability testing is an excellent way to test your solutions with real users quickly. But how exactly do you perform a guerrilla test?

Here are some steps and recommendations you can follow to run a successful guerrilla test, including planning your testing sessions, finding the right participants and place, and more.

Although guerrilla usability testing requires fewer resources than traditional user testing, that doesn’t mean less planning. Before approaching the participants, get ready by writing a script for your testing session. Think about what you should test, the scope of your research, and the tasks you want the participants to complete.

To start, prepare a realistic prototype to test with users. The fidelity of your guerrilla testing prototype will depend on where you’re up to in the design process. If you plan on testing very early—which is generally a good idea—some designers say that a paper prototype or drawings will do.

However, UX designer Nick Babich disagrees:

Instead, he advocates at least using some kind of working prototype:

Once you have your prototype, it’s time to map out the specific tasks that the users will be carrying out. The standard tips on writing usability tasks apply: keep your list of tasks short and simple, avoid leading questions, and use as few steps as possible. Simplicity is especially important for guerrilla testing, as participants will lack some of the context around your product that they’d have in a conventional, pre-arranged test.

So make sure your research objectives don't require any prior feature-specific knowledge of your product. You could even try it out on a friend or family member to be safe. For the full guerrilla test rehearsal, ask them out of the blue over breakfast.

Finally, limit the scope of your test, so it specifically focuses on one core user objective. You don’t want to take up too much of people’s time—10-15 minutes tops—and the more precise your testing hypothesis, the easier it is to compare results between tests and spot trends.

Since the main differentiator of guerrilla testing is finding test subjects in public places, getting this part right is key. The one potential disadvantage of the guerrilla approach is that the people you test might not represent your target demographic, which makes your results less reliable.

Here’s a few tips on finding the right kind of participants:

It’s important that your guerrilla test participants resemble your target audience, so keeping these tips in mind will narrow your search.

Once you’ve found a participant who seems to fit your target profile, the test itself should unfold just like a normal usability test. Get people to share their thoughts and opinions with the think-aloud protocol, leave open-ended questions until the end, and make a note of common trends in user behavior.

There are just a few extra things to be aware of when honing your in-field testing technique:

The most common reasons that designers give for skipping user testing are time and money. But paradoxically, these are also two of the most important reasons you should test—no matter what. As designer Jonathan Weber says:

So if remote usability testing is not an option, guerrilla testing is still a massive improvement on no testing at all. And besides that, it’s a chance to get out of the office and talk to potential users—which is both important, and fun.