SUS

SUS: System Usability Scale

SUS or System Usability Scale is a questionnaire based metric used to evaluate the usability of a system or software. It is widely used in the industry to measure the effectiveness, efficiency, and satisfaction of a particular system or software.

How does SUS work?

The SUS questionnaire consists of ten questions, which are rated on a five-point scale ranging from "Strongly Agree" to "Strongly Disagree." The questions are designed to evaluate the usability of a system or software from various perspectives, such as learnability, efficiency, and user satisfaction.

Why is SUS important?

SUS is an essential tool for evaluating the usability of a system or software. It helps developers and designers to identify the areas that need improvement and to make necessary changes. It also helps companies to compare the usability of different systems or software and choose the best one for their business needs.

How to use SUS?

To use SUS, you need to administer the questionnaire to a group of users who have used the system or software. Once you have collected the responses, you need to calculate the SUS score using a formula. The formula is as follows:

Score = (Sum of all scores - 5) * 2.5

The SUS score ranges from 0 to 100, with a higher score indicating better usability. A score above 68 is considered above average, while a score above 80 is considered excellent.

Other ways to measure usability

While SUS is a popular metric for measuring usability, there are other ways to measure usability as well. Some of the other metrics include:

• Task completion rate: This metric measures the percentage of tasks completed by users within a given time frame.
• Error rate: This metric measures the number of errors made by users while performing tasks.
• Time on task: This metric measures the time taken by users to complete a task.

It is essential to use multiple metrics to evaluate the usability of a system or software to get a comprehensive understanding of its usability.