How to conduct fool-proof usability tests

Usability testing is a key step that we’ve been utilizing for many years. Through a process of trial and error, we’ve gained valuable insights on how to avoid common pitfalls in usability testing while also securing the most useful results. l. In this series of articles, we’ll be sharing our experience in how to conduct high-quality usability tests.

Michal Voják

Co-founder / userUP Leader

Our guidance will bring you closer to reliable usability testing in your design process.

Part 1: Introduction to usability testing
Part 2: Preparing your usability test
Part 3: Running your usability test
Part 4: Usability test evaluation

Part 1: Introduction to Usability Testing

In the first article of this series „How to conduct fool-proof usability tests“, we would like to explain what exactly is a usability test, what is its purpose and how you need to conduct a reliable usability test.

What is a Usability Test?

The usability test is an experiment where we try to identify the natural behavior of a user on a specific webpage, e‑shop or app, particularly to find difficulty the user may experience that complicates or hinders their ability to use the site. The core benefit of conducting usability tests is to find problems that were not initially apparent during your design process. This gives you a chance to improve your product, services or function before reaching development and before your customers start using your product in earnest. Usability testing is a key Product Discovery step that helps to lower the risk that we make a product or feature that our customers simply don’t need.

Testing your product during the production process allows you to find the pain points in your design. Catching these issues via usability testing with your prototype will help you save money in the development phase by eliminating design faults before launch. 

In my 7 years in the UX field, I’ve seen a number of issues that have led me to novel insights on the value of usability testing in the field. For this reason, I’ve decided to write this series on how you can conduct usability research and what you should be thinking about.

Why you should conduct usability testing

Conducting a usability test helps you to troubleshoot issues your users may run into in your prototype. For example, you could see during this experiment that there is an issue with the e‑shop checkout basket or realizing that the contact information is not visible enough on the site. 

The most common problems you can identify with usability testing:

  • Incorrectly named element-Users cannot tell what the name means or where it would lead.
  • Hard to find something – Users cannot find the information that they are looking for
  • Accessibility issues – Users experience difficulty clicking on some buttons or the button looks disabled.
  • Mismatched content – The user expects to find some information on the page but the relevant information is not present.
  • Incorrect element behavior – e. g. the user expects that hovering over an element means it is clickable, but it is not the case.

How many and what respondents to invite?

How many respondents

For a single test, five respondents is enough. This number can usually find approximately 70–80% of usability problems. If you'd like to know more about respondent numbers for usability testing, you can visit this webpage: 


Whom should you invite to testing?

You should always try to invite your target group for your product or services. Since the target group should be accustomed to your product or service, they can offer the most relevant feedback. Additionally, since they are your target group, their feedback is extremely valuable to consider during the design process. Your target group in the context of usability testing doesn’t have to specifically be your existing customers, but could easily include individuals that have the same wants and goals as your customers. 

If it is not possible to invite members of your target group, you can attempt to include people with a similar profile to your target group. However, since these individuals don’t necessarily represent your end users, not all feedback is as relevant in this case.

Where you can get respondents

Maybe you’re asking yourself, where can I get respondents for my product? Mostly, it’s easier than it sounds. You can start with people around you, ask your friends, friends of friends or your colleagues in your company or on social networks. 

Another relevant spot for recruiting respondents could be at your store's dispensing point or you can try recruitment by forms on your website. In some cases you can use your database of customers. It really depends on your own imagination. If everything fails you can always get respondents by agencies which can find really specific target groups very well but it is more expensive.

Motivation for respondents

Respondents need some motivation to get their attention. For one respondent, the test could represent a time commitment of 2–3 hours depending on where they live (including travel time, while the test itself takes max 60 min). Often, the simplest way to motivate respondents is with monetary compensation. The fee is generally somewhere between $25 – $75 (but it depends on the country and target group). It is not always necessary to pay the respondents, as you can also offer discounts on your products or something else that your respondents may want.

To be continued

In the next article, „Preparing the Usability Test“, you can look forward to advice about the administrative staff required to conduct the usability test, preparing relevant scenarios as well as important technical requirements.


userUP helps you with

About the author

Michal Voják

Co-founder / userUP Leader

Michal is a pioneer in product discovery! He is behind the idea of this tool.

Related articles

In our first article titled „Usability Testing Introduction“ I explained what are Usability Tests,…

Preparing Your Usability Test

This article is a part of the series, „How to conduct fool-proof usability tests.“

Running Your Usability Test