“Data collection can be a challenge when testing mobile devices. Because of mobile devices’ small size, it can be difficult to get a clear video recording of participants’ interactions with a device. This is particularly true for touchscreen devices, because when a participant interacts with a touchscreen, his or her hand also obscures the user interface. This can make is difficult to see what buttons a participant presses.”
Link: Usability for Mobile Devices (uxmatters.com)
