Käytettävyyskertoimien

Käytettävyyskertoimet, or usability coefficients in English, are metrics used to quantify and assess the usability of a product or system. These coefficients help in understanding how easily and effectively users can achieve their goals with a given interface. They are crucial for designers and developers aiming to improve user experience.

Commonly, usability coefficients are derived from usability testing. During these tests, users are observed performing specific tasks, and various data points are collected. These data points can include task completion rates, time taken to complete tasks, number of errors made, and subjective user satisfaction. By analyzing these metrics, one can calculate coefficients that represent different aspects of usability.

For example, a task success rate coefficient would indicate the percentage of users who successfully completed a given task. A time-on-task coefficient could represent the average time it takes for users to finish a task. Error rates can be quantified to show how prone users are to making mistakes. Furthermore, post-task questionnaires can yield satisfaction coefficients, often measured on a Likert scale.

The goal of using usability coefficients is to provide objective data that can inform design decisions. A low success rate or a high error rate, for instance, would signal areas in the design that need improvement. By tracking these coefficients over different design iterations, teams can measure the impact of their changes and strive for optimal usability. These coefficients are not absolute values but rather comparative tools used within the context of specific user groups and tasks.