Because humans do unpredictable things, expect a labor-intensive UAT (humanoid) testing process. Humans follow a prepared script and execute steps over a set period of time to test for errors and performance problems. In addition to testing concurrency, capture other critical information from human testers:
- Use of the model with different bandwidths
- Use of different operating systems
- Location differences
- Browser compatibility
This data that can help identify and resolve usability issues.
You will not know if the tester follows the script as you might anticipate. If a tester becomes bored or distracted, steps can be missed and areas of the model with bugs can go undetected.