How do you know when you have achieved a really good UX?
How do you know if you've created a good UX? By testing early and often, and making any changes as necessary. If you have the budget, you can run prelaunch user experience research. This type of research gives you usability feedback from people who are representative of your target audience.
How is UX trust measured?
To measure trust, we use a set of 12 statements on a 5-point likert scale where 1 indicates strongly disagree and 5 indicates strongly agree. These 12 statements can be used by a UX practitioner to make a questionnaire when evaluating trust with a product or servce. Learn more about trust score in Documentation.