Which of the following is NOT a useful KPI in UX research?

User feedback ratings may seem useful for gauging user satisfaction, but they can be subjective and influenced by factors outside the actual user experience, such as personal feelings or external circumstances. While they can provide insights into general sentiment, they might not reflect the true usability or effectiveness of a product.

In contrast, time on task, conversion rates, and user error rates offer more quantifiable and objective measurements of user interaction and success. Time on task helps identify how efficiently users can complete a task, revealing potential usability issues. Conversion rates indicate how well a product or service meets its intended goals, such as making sales or sign-ups, and user error rates can highlight specific areas where users struggle, prompting targeted improvements. These metrics provide concrete data that helps inform design decisions and enhance overall user experience.