What is the USERindex?

The USERindex is a standardised means of measuring the user experience of a digital interface.

Let’s take a closer look at that statement:

We say “digital interface” because we are well aware that today, when we speak of “digital” we are no longer only referring to computers and desktop/web applications; we are referring to a series of devices such as wearables and smartphones as well as products which are recently being equipped with digital interfaces such as cars and fridges, for example.

While usability refers to how successfully a user can carry out a task with a given product, User Experience takes a broader view, taking the user’s individual perception of his entire interaction with the product and even the brand into consideration. Today, the success of a digital interface is determined not only by the functions it offers but also, and maybe even more importantly, by how the user feels about interacting with it. The subjective, more emotional factor is becoming the deciding factor. The USERindex takes this into consideration.

Four factors and 10 aspects

We believe that an exceptional user experience is determined by 4 factors (which we call USERindex dimensions):

  • Usefulness
  • Satisfaction
  • Ease of use
  • Reliability

USERindex dimensions

Each dimension is in turn defined by aspects which comprise both very objective facets of a good user experience such as the accuracy of information and the responsiveness of the interface, as well as very subjective ones such as whether the user liked using the interface.

USERindex – Click to view image in separate window

The USERindex comprises 10 questions which have been worded neutrally, avoiding jargon and which can be applied to any digital interface, be it a web application or a wearable device. This makes the index very powerful because it can be used to compare the user experience of different products even if they are very dissimilar in function and interface type.

Dimension Aspect Statements
Reliability Performance I felt the site responded quickly
Accuracy I found the information on the site to be accurate
Usefulness Effectiveness The site does what I need it to do
Usefulness The information on the site was useful to me
Ease of use Ease of use I found the site easy to use
Navigation It was easy to find what I was looking for on the site
Learnability It didn’t take me long to learn how to use the site
Efficiency It didn’t take me long to complete my task on the site
Satisfaction Appeal I found the design of the site appealing
Engagement I liked using the site

We researched our choice of positively expressed statements (as opposed to a mix of negative and positive statements) and deliberately decided to go with them because we don’t believe that we need to negatively word the statements in order to achieve more accurate results. This has also been proven in a study where the SUS was deployed in both its original format of both negative and positive statements as well as an entirely positively worded version and the variance was found to be negligible (SUStisfied? Little-Known System Usability Scale Facts).

We believe that the 4 dimensions are correlated and thus improving one dimension will have an impact on the others.


  • The USERindex measures more than just the usability of a digital interface; it takes the emotional aspect of user engagement into consideration
  • The USERindex is a tool for measuring the holistic user experience of a digital interface
  • The USERindex can be used to compare the user experience of different digital interfaces regardless of the devices or technology they run on
  • The USERindex can be used to continuously monitor the evolution of the user experience of your digital interface over time.

Read more:
How to use the USERindex