Guerrilla Testing: How To Introduce It In Your Next UX Project

Guerrilla Testing: How To Introduce It In Your Next UX Project

When it comes to user research, sometimes you have to invest more to get more. Other times, you can avoid the expense. Take this Google statistic for instance: did you know that 85% of core usability problems can be determined by observing just five people using your application?

When working with a limited UX budget and a brief timeline, guerrilla usability testing is a cheap and fast way to identify user trends and observe user behaviour to improve your user interface. In fact, it has been proven that simple guerrilla-style usability testing can increase conversion rates, improve customer satisfaction and retention, and reduce maintenance and project risk.

So if you are searching for a way to research smart and research fast, it is time to try the guerrilla approach. This article will take you through all the basics, plus let you in on some industry secrets.

Let us get started.

What is Guerrilla Usability Testing?

Like other usability techniques, guerrilla usability testing is a way to evaluate how effective an interface is by testing out its visual design, functionality and general message on its intended audience and capturing their responses.

What makes guerrilla usability testing unique is that participants are not recruited in advance. Instead, members of the public are approached by those conducting the study during live intercepts in cafés, libraries, and malls, or in any other natural environment.

Arguably this makes guerrilla usability testing a quick, cheap and hassle-free way of gathering feedback from target users.

The Process of Guerrilla Usability Testing

Guerrilla usability studies are structured around critical research objectives defined for the user research portion of a UX project. Nevertheless, they are usually flexible enough in nature so that they can be adjusted according to the evolution of the user research.

Study sessions are generally short, often lasting between 10-15 minutes according to UX specialist Nick Babich. Guerrilla typically involves fewer participants than other types of studies (between 6 and 12, according to Box UK’s Gavin Harris), allowing enough time for a thorough assessment of each participant’s behaviour.

Guerrilla usability testing is relatively low maintenance. At its most basic, test participants are set a series of tasks to complete, and the research team will note any problems that occur during the test.

You will not need much equipment to get started – just a computer to run the test, a moderator and somebody to observe and take notes. You could also record participants’ responses using a screen recorder to save resources and time – but it is always a good idea to have someone else there to observe participants’ reactions and body language in each part of the test.

You should be testing on prototypes made in tools, such as Justinmind, where you can make your tests and essential or interactive as you like.

Guerrilla Usability Testing Deliverables

Guerrilla usability testing deliverables are usually qualitative rather than quantitative, as you will be directly assessing participants. Qualitative research tends to ask ‘why’ rather than ‘how many’ or ‘how much’. The goal of this type of testing is to inform design decisions for ongoing projects and identify usability issues, rather than assess the usability of an existing interface.

Findings and insights are based on the research team’s interpretations of the participants’ responses. Here are some of the types of deliverables you can expect after a round of guerrilla usability testing, as suggested by Gavin Harris:

  • A test plan document outlining the proposed test time frame and key research objectives.
  • A video combining screen and participant recordings.
  • A summary report covering key findings and next steps.
  • A presentation covering key findings and the following steps.
Should You Perform Guerrilla Usability Testing?

Yes. Guerrilla usability testing should be performed when your project calls for quick and cheap testing, such as when you need to validate design assumptions early in the project life cycle, or in a project with a low budget.

Ad hoc user research, like the kind you can achieve through guerrilla usability studies, means avoiding recruiting ‘on spec’ participants whom you may have to travel to reach (or vice versa) or pay for their time. Elizabeth Chesters on What Users Do says that this type of testing will get you in front of anyone who says yes, and as such, is a right way of setting quick design baselines and measuring improvements.

However, bear in mind that ad-hoc user testing will return less accurate results, as you will not necessarily be testing your target user base. In fact, you will likely receive a mixture of users who are new to your product or the market as well as existing users. In this way, guerrilla usability testing is best limited to user research that does not require advanced knowledge of a specific device or feature.

How to Get Started With Guerrilla Usability Testing

As you can see, guerrilla usability testing can be an effective way to get feedback from users in UX design projects. So now let us see how to get started with your guerrilla usability study.

What Should You Test?

As mentioned, guerrilla usability testing is a low-pressure approach to user testing. However, this does not mean you can get away without doing your homework.

Before you start bothering the folks down your local coffee shop, get organised by writing a test plan that defines what is working well for your product, and where improvements can be made.

First things first, think about what you are testing. Having a firm understanding of the scope of your user research is key to a successful guerrilla usability study. So figure out what it is you want users to be able to do. Maybe you want them to sign up for your newsletter or learn about the features of your product? Whatever the goal, write it down and be specific.

You may want to use Google Analytics, heat maps or A/B testing to help you spot trends and figure out what needs to change. Analytics will tell you what is going wrong but usability testing will tell you why.

Based on your findings, come up with a list of tasks for test participants to complete. For instance, if you want to optimise your checkout experience, your task list might look something like this:

  • Add an item to the cart
  • Browse additional items
  • Go to the checkout page
  • Sign in
  • Change the delivery address
  • Confirm the transaction details
  • Print the payment confirmation
  • Locate the payment authorisation in the email inbox

Once you have come up with your tasks, turn them into scenarios to pull them together and make them more accessible for participants to read and follow. Learn more about creating scenarios in this article.

What Should You Not Test?

Remember that to keep your usability testing light, you will probably need to reduce your user research scope. Amanda Stockwell, President of Stockwell Strategy, starts out by determining how she would do her research if she had unlimited time and resources.

Then she will work backwards to find the test elements she can toggle to make it work for her actual budget, pointing out that the first place she looks to cut is the scope of the research question.

In our checkout experience example, you could cut out the following tasks:

  • Browse additional items
  • Change the delivery address
  • Print the payment confirmation

You can also reduce scope by scaling down on the number of test participants and keeping your wireframes basic.

When Should You Test?

A common mistake in user research is performing usability studies too late in the design process. Early testing helps teams validate their ideas before they spend time and resources on building them out, and has proven to be cost-effective in the long run.

As usability expert Jakob Nielsen points out, “Every hour you can cut off user training is one hour more for productive work and one hour less to pay an instructor.”

Due to its low cost and easy step up, it is easy to get started early on with guerrilla usability testing in the design process. What is more, you have got the flexibly to choose your test medium (e.g. pen and paper, a low-fidelity wireframe or a fully-functioning prototype).

Also, remember, guerrilla usability testing does not have to be limited to project kick-off. In fact, you can pretty much incorporate it into any stage of your design process, from identifying errors early on to conducting iterative design testing in Agile sprints.

Where Should You Test?

The location for your usability study is important and can have a direct impact on the test results. To ensure you get the best feedback:

  • Choose somewhere you can charge your laptop – you do not want to run out of juice halfway through a session.
  • If you require internet access, you will need to choose a location with Wi-Fi connection.
  • If users are to respond to audio, do not go to a library.

As UX Booth’s David Peter Simon suggests, let context drive your study.

How Do You Find the Right Participants?

To get the most relevant user feedback, you need to engage with the most relevant participants. When thinking about whom to approach, consider who will be using your product above all else.

When looking for the right participants, it is often a case of being at the right place at the right time. If you are participant-hunting in a café, aim to conduct your study as people are picking up their morning coffee. Tip: people tend to be friendlier on Fridays, and if there is free food!

UX-UI Designer Flora Ganther offers up her own guerrilla usability testing experience here, where she explains that being in the wrong place at the wrong time can have disastrous consequences.

How Will You Test?

Kicking off your guerrilla usability study is as simple as walking up to someone and asking them if they can spare a few minutes of their time.

Once someone agrees to participate, start by explaining them to them how the test works and how long it will take. Be as truthful as possible, i.e. if the test is going to take 15 minutes, do not tell them it will take 5. Likewise, do not take up more of their time than initially stated.

To collect the most accurate feedback, ask participants to think aloud. You may have to prompt them to do so throughout the test. Ask them to save questions to the end.

Once you have explained the test, let them get started. Be sure to take good notes of what people say during the test. You want to record how easily they were able to complete each task, how long it took them and the number of errors they made.

Try not to speak unless necessary, and give them time to think about their responses. Once the test is complete, it is time to address any questions. Markus Pirker from User Brain suggests turning this part of the study into a customer interview, should you be lucky enough to test with people from your target audience. Find out how they found the test, which bits they found most challenging and their general feelings about the interface.

Tip: if your budget allows, treat the first one or two sessions as a practice round to allow for nerves and technological mishaps.

Leveraging Insights From Your Guerrilla Usability Study

When your guerrilla usability study is complete, it is time to collect your data, identify usage patterns and share your findings with your team. There are several ways to share your findings, depending on your audience (for example, designers, developers and stakeholders).

For instance, you could use a report template, create charts to represent any interesting metrics data collect, place findings directly in the Scrum backlog as design ideas or create 2-3 minute video clips with test highlights (a great way to keep things interactive and evoke empathy).

When Airbnb conducted guerrilla usability testing, they gathered and ordered user feedback by the level of frequency of comments related to booking, filters, search and navigation.

Your findings from guerrilla usability testing will have a direct impact on how you implement design fixes, proceed with redesigns and ultimately how users receive your site or app.


Although guerrilla usability testing may not be the best choice for every UX project, it can be a quick and effective approach to learning more about your users concerning your interface.

Moreover, remember, usability testing is crucial to the success of your website or app, so even simple feedback from users is better than none at all.

This article originally appeared on Usability Geek

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