Also called: Hallway Usability Testing
Relevant metrics: Usability, Customer feedback
How: Conduct 3-5 brief usability or product tests no longer than 15 minutes with users merely looking like somebody from your target audience to reveal valuable insights from outside perspectives. Approach a stranger, ask if they'd like to participate, give them a few tasks to do, observe their interactions, and ask about their experience.
Why: Some would argue that testing on more than 3-5 users is a waste of time and resources – some the opposite. Regardless of what is considered correct, testing on zero users yields zero insights. Conducting just a few small user tests with random lookalike users can quickly reveal valuable insights in a matter of hours rather than days and will as such allow faster design iterations.
This experiment is part of the Validation Patterns printed card deck
A collection of 60 product experiments that will validate your idea in a matter of days, not months. They are regularly used by product builders at companies like Google, Facebook, Dropbox, and Amazon.Get your deck!
Before the experiment
The first thing to do when planning any kind of test or experiment, is to figure out what you want to test. To make critical assumptions explicit, fill out an experiment sheet as you prepare your test. We created a sample sheet for you to get started. Download the Experiment Sheet.
Elaborate usability tests are a waste of resources
As early as in year 2000, Jakob Nielsen claimed that “The best results come from testing no more than 5 users and running as many small tests as you can afford.” The reason being that the number of new usability problems found and learning obtained drastically decline the more tests you conduct to a point where it isn’t of any significance. He claims that after the fifth user, you are practically wasting your time by observing the same findings repeatedly, but not learning anything new.
There are no facts inside your building
Go outside. Go to locations where you will find target users and ask them to use your prototype for a quick minute or two. The guerilla approach to usability testing tries to remove barriers and challenges related to scheduling, papwerwork and setup. Instead the focus is to get out of the building to find real potential users in the wild.
After the experiment
To make sure you move forward, it is a good idea to systematically record your the insights you learned and what actions or decisions follow. We created a sample Learning Sheet, that will help you capture insights in the process of turning your product ideas successful. Download the Learning Sheet.
In his seminal 1994 academic article, Jakob Nielsen demonstrated that using discount usability testing methods yielded much better cost-benefit ratios over more expensive lab-based versions and that the point of diminishing returns on how many tests to carry out was around 3-5.