What does the user experience SLO measure?

The user experience Service Level Objective (SLO) specifically measures user satisfaction, and one of the established methods for quantifying this satisfaction is through the Apdex score. Apdex (Application Performance Index) is a standardized way to measure the performance experienced by users, focusing on user satisfaction with the response times of applications.

In essence, Apdex helps to interpret the quality of user experience in terms of how responsive the application feels to users. A higher Apdex score indicates a higher level of user satisfaction, as it takes into account the proportion of satisfied, tolerating, and frustrated users based on their expectations of application performance.

The other options provided do not directly measure user satisfaction. The number of applications downloaded is a metric related to usage rather than user experience. The time taken for page loads reflects performance without directly assessing how users feel about that performance. Likewise, the frequency of user logins indicates user engagement but does not necessarily reflect satisfaction with the application's performance or experience overall.