How can you test and validate your user interface design using real feedback?

This also includes assessing Task Success using direct & indirect metrics. Direct task success measures how efficiently users accomplish specific tasks related to the primary interface goals. E.G., in e-commerce, the % of users who complete a purchase without errors. Indirect task success involves instances where users explore before task completion revealing potential usability issues. e.g. for an e-commerce site, it captures users navigating different sections, making detours or consulting help resources before making a purchase. Time on task metrics help track how long users take to complete tasks, again directly & indirectly. Finally, you can use subjective metrics like SAT, user effort score (UES), ease of use or SUS.

When choosing between moderated and unmoderated testing for UI in later project stages, think about how much you want to interact with users. In a moderated testing you get detailed feedback and can ask questions. This is great when you want to fine-tune a specific part of your UI, like a complicated checkout process. On the other hand in an unmoderated setting users go through your UI on their own. You gather lots of data quick & automatically. This is useful when you want to see how well the UI works for a large group, like checking if most users can easily search & find products. Your choice depends on whether you need detailed insights (moderated) or quick, big-picture feedback (unmoderated).

End-to-end testing is best suited for assessing the seamless functionality of an entire system or user journey in later stages. It's valuable in ensuring that all tech components work harmoniously and uncovering integration & performance issues. In contrast, more targeted testing is ideal for evaluating specific interactions and elements within a system, making it effective for fine-tuning usability and isolating usability-related concerns. The choice should depend on whether you're focused on tech integration or individual user interactions. e.g, E-to-E testing is valuable for ensuring an entire e-commerce purchase process works flawlessly, while targeted testing can identify issues in tasks like product comparison, searching, or checkout.