How does SUS assign scores?

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This process is similar to a “grading curve” based on the distribution of all scores. For example, a raw SUS score of 74 is converted to a percentile rank of 70%. A SUS score of 74 has a higher perceived usability than 70% of all products tested. This can be interpreted as a B- grade.
You need to score above 80.3 to get an A (the top 10% of results). This shows that users are more likely to recommend the product to a friend. If you score an average of 68, you'll get a C, and anything below 51 will get you an F (and you'll be in the bottom 15%).
Even though the SUS score can range from 0 to 100, it is not a percentage. While it is technically correct that a SUS score of 70 out of 100 represents 70% of the maximum possible score, a score at finland whatsapp number data this level would indicate that the app tested is above average. In fact, a score of 70 is closer to the average SUS score of 68. In fact, it is more appropriate to call it 50%.
When communicating SUS scores to stakeholders, and especially to those unfamiliar with SUS, it is best to convert the raw SUS score to a percentile so that 70% truly means above average.
SUS measures usability and learnability.
While the SUS was intended to measure perceived ease of use only (one dimension), recent research shows that it provides a global measure of system satisfaction and usability and learnability subscales. Items 4 and 10 provide a learnability measure, and the remaining 8 items provide a usability measure. This means that you can track and report on both the subscales and the global SUS scale.
SUS reliability.
The reliability of a scale refers to how consistently users respond to items. The SUS has been shown to be more reliable and detect differences with smaller sample sizes than domestic questionnaires and other commercially available ones.
Frequently asked questions about SUS.