How to do a complete mobile guerrilla user test in under half a day

Often you need quick and regular feedback on what you’re designing to help you adjust designs and prototypes early. Here’s a breakdown of how I have carried out guerrilla user tests, including prep time and analysis of the results in under four hours. This applies for doing it internally at big companies where suitable testers are easy to come across, as well as going out in public and finding people. Sometimes called hallway tests or cafe tests, guerrilla user tests are basically any time you don't have a formal test lined up.

Ideally you’d have two people to carry out a test, one to facilitate and one to take notes but that isn’t always possible. So this method works for when you need some user feedback on your product and you’re a one-man band or the only person prepared to do it. It works best for testing on mobiles as you can do it anywhere.


30 mins

You will need:

User testing prep notes


1 hour


2 hours 15 mins

Here’s how to tackle the analysis stage that some designers are tempted to ignore. This is an important step to take so you record your data accurately. As you were conducting the test you can think you already have the insight you need but it is common to misremember what actually happened: watching it back helps you check exactly how serious each issue was and helps you spot things you might have missed. Also it means you’ve got the data in a useful format that can be accessed later and shared with others, as proof the test actually happened.

User testing analysis post-it notes

  1. Get the videos off your recording phone and onto a laptop, or even better a shared drive.
  2. Watch the first video and note down on a post-it note any time the user struggles, is unsure, finds a bug, or anything else of note. For each user put an identifier on each post-it note or use different coloured post-its, this way you’ll know which test to refer back to for each issue.
  3. Repeat for the other four tests. Each one should take about 15 minutes.
  4. Now you should have a load of post-it notes with some hopefully repeating themes. Do a bit of affinity mapping and cluster together the common themes and issues. This should take about 45 minutes to give yourself time to play with the groupings and possibly discard irrelevant ones.
  5. Finally, crack open a Google Doc or note of some form and write up the issues you’ve seen in a list ordered by the most recurring. Or prioritised however you wish. Link off to where the videos are stored and this doc can act as your index and report that the user testing took place.
Last updated on 16 October 2015

ux / user testing / prototypes / mobile / app design / guerrilla testing /

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