Sat. Jan 21st, 2023



The correctness relates to how closely to the intended product the outcome is. For example, if you are designing a logo which should be 1024×1024 pixels, one test of correctness is the size.

Similarly, if a video or animation is the intended output, the length would be an obvious correctness metric.

Anything from the requirements that defines a physical characteristic would lend itself to a correctness test.

Examples include:

  • Is the length correct
  • Do the effects work as intended
  • Are any elements missing
  • Is the file size acceptable

These tests can be easily completed by the designer/author – they are compliance checks with definite yes/no outcomes, and are not based on opinion.


These tests, unlike the correctness tests, are rooted in opinion and interpretation. That is, you may design something that you think looks fantastic, but it is difficult to be objective when assessing your own work like this. When you test the presentation, you should consider:

  • Does it work at different sizes
  • Does it work with and without backgrounds
  • Does it reflect the look and feel that was intended
  • Is the message conveyed clearly

These questions are better asked by other users – consider a questionnaire where you can collect feedback from several test subjects, and collate this.

In the real world, this would be done with test panels. It is important to understand that as the purpose of using test subjects is to remove any bias for or against designs that you may have, the selection of the test subjects should ensure a wide cross-section of users is represented. That means that you wouldn’t use a group of teenagers to gather feedback on a design that was intended for adults, and vice versa.

Even with a test panel, you will likely have varying levels of enthusiasm towards designs and opinions on their effectiveness. This is fine. Part of your job when you collect this evidence it to look for trends – if 8 out of 10 people think a message is clearly conveyed, then you could probably disregard the two who disagree.


This set of tests will determine whether or not the product works as intended with the range of hardware or software that it should.

If you design a website, you may need to verify that it works correctly on:

  • Windows – Internet Explorer, Chrome, Firefox, Edge, Opera
  • MacOS – Safari, Chrome
  • iOS – Safari
    • Small screen (e.g. phone)
    • Large screen (e.g. tablet)
  • Android – Chrome
    • Low resolution screen
    • High resolution screen

The same applies for videos – check that the format is appropriate and delivers the features required for different platforms. For instance, some video formats work well for internet streaming, whereas others don’t. And remember – not all systems have or support all video and audio codecs.