Beta is too late
Usability testing and user acceptance testing are two user experience design processes. They sound similar, but they’re fundamentally different.
User acceptance testing, or beta testing, is done on a product that's already been built. It’s used to ensure that the product works according to the requirements.
Usability testing, on the other hand, informs the product requirements. It’s used to identify flaws and points of friction in the prototype, uncover opportunities to improve the product, and learn more about the users.
I’m talking about product design here, but this is true for most creative disciplines.
We, the experts, tend to work our magic behind closed doors. After all, isn’t the expert supposed to know what works and what doesn’t? But we’re also closing the doors to the complexity of the realities we’re hoping to affect.
Whatever the project is, engage your people as early as possible, make learning the common thread in your process. It’s way harder and much more expensive to improve the product when it’s time for beta testing.