What is SUS? A Comprehensive Guide

What is SUS? The System Usability Scale (SUS) is a popular and easy-to-administer questionnaire used by usability practitioners and evaluators. It provides survey participants with a numerical score to describe the overall usability of a system, product, website, or application. It was developed by John Brooke at Digital Equipment Corporation’s Cambridge Research Laboratory in 1986. The SUS is the most commonly used measure of usability and has been used for decades to evaluate products and services all over the world.

Why use SUS?

The SUS was designed with the goal of making it easy to measure the usability of any system, product, website, or application. It is a simple, quick, and effective measure of usability. The questionnaire consists of ten items which measure the usability of a product according to four dimensions: efficiency, effectiveness, satisfaction, and ease of use. The questionnaire has only five response options, making it quick and easy to complete, as well as simple to score. The SUS has also been found to be consistent across different products, making it a reliable and valid measure.

How to Calculate SUS?

To calculate SUS scores, responses to the ten items are summed and then multiplied by two. The resulting score is an estimate of the overall usability of the system, product, website, or application. Scores range from 0 to 100, with higher scores indicating higher levels of usability. Scores of 68 or higher are typically considered to be indicative of an acceptable level of usability, and scores of 80 or higher are considered to be indicative of excellent usability.

The SUS provides a simple and effective measure of the usability of any system, product, website, or application. It is a great tool for practitioners, professionals, and evaluators alike and can easily be incorporated into a usability evaluation. In the end, the SUS provides the end user with a quantifiable means of assessing the usability of a system, product, website, or application.