Doing usability tests
As said before, you can combine usability testing user interviews and optimize time with the same user; the ideal time would be between 45 and 60 minutes.
Pro tip: test the script prepared in advance. Although you don't need to strictly follow the script, you will want to make sure you know the purpose of the test and what questions you want to have answered. Ask the users to give their first impressions on entering the site, app, or using a service or product. If they have already used or had previous experience with your site, app, product, or service, ask where they usually navigate and what they usually do. Let them be the expert by explaining to you how to do or use it.
Even before starting the test, remind the user that they are not being tested and that their participation aims to improve the navigation of the product, app, or product and service tested. This note will help the user feel more relaxed and confident during the test. They shouldn't feel like they are being tested at all. Take care to not interrupt the testers, let them feel free to speak and encourage them to think out loud, allowing some quiet moments so that they can think, as you analyze their navigation, use, and reactions.
When we are asked about the ideal number to obtain valid results for the usability test, we can highlight what expert Jakob Nielsen suggests: five test users should be enough, since the results begin to be repeated from the sixth user, according to him (as we saw in Chapter 2, Identifying UX Issues – UX Methodologies).
You can run the user interviews in person, in a laboratory, in your company, somewhere indicated by the user (home or office), or even use online platforms, as was said earlier. You can also do tests that don't involve an interviewer, or unmoderated tests, by using online tools such as fivesecondtest.com, usertesting.com, usersthink.com, UserZoom.co.uk, userbrain.net, UsabiltyHub.com, userfeel.com, usertest.io, WhatUsersDo.com, trymyui.com, among many others (you can see examples here: remoteresear.ch/tools). Loop11.com is a great tool for this purpose:
In an unmoderated test, you can use the same test script, defining tasks that must be tested by the online user tester, who is encouraged to speak and explain aloud their actions while browsing the app or website. All of the test is recorded to be watched later.
There are other test methodologies that you can combine besides user interviews, such as card sorting, a technique used to find out how the user classifies certain information in their mind by doing activities with cards to test organizational areas or content of your website. You can also use tree testing to test the site navigation tree. Tree testing is a great validation technique for content structure, which allows you to validate users' performance by finding particular content or performing a certain action without any visual interference.