How Many Test Respondents Do I Need?

“How many test respondents do we need for a good user test?”

We get asked this question all of the time. Noted User Researcher Jakob Nielsen already shares a great answer to this question on his blog¹, so we will just summarize his thoughts here.

1. Basic Usability Study

How to Test Design Layout Versions

Optimizely has a great product for A/B testing single variable changes in production. For example, it is easy to test things like: does changing this button size impact conversion rates?

But what if you want to test an entirely different design layout? Do you have to code it up and release the new design to production to get feedback?

The short answer is NO.


Here is how to run user tests on design layouts:

Asking Good Questions During a User Test: Don’t Lead the Witness.

As I mentioned in a prior post, the key to great questioning during a user test is respecting natural human limitations.

One of those limitations is that humans can be unintentionally persuaded to give you the answer you want to hear. Thus any test creator must take great care to not create leading questions.


Below are two questions that could be asked during a user test. Can you guess which one is a good question and which one is not?

How Many Questions Can I Ask During a User Test?

I get asked all the time, “how many questions is a good number to ask in a user test?”

The answer is actually time based, not quantity based.

Lean ser Testing

The 5 minute rule:

The Key to Asking Good Questions During a User Test

The key to great questioning during a user test is respecting natural human limitations in cognition.

While this sounds obvious, test creators often ignore natural human limitations because they want to get a specific question answered.

Key to good user testing questions:

When creating user tests, keep in mind, people are good at explaining why something is confusing, but bad at creating solutions. Tweet this