Ask someone to stand behind the participant with a camera, filming over the person's shoulder. A tripod can help a lot:
- You can record the participant's gestures and some of the context.
- The testers can use their own mobile phone. This is important because the participant feels more comfortable with their own mobile phone and without having to learn how to use a different device. Android phones vary greatly in size, format, and even in the placement of the fixed buttons.
- The participant may feel tense because there is someone behind him and you can not see exactly what he is doing.
- You need to ask the person to leave the phone in silent mode on the desk, or it can be difficult to adjust the focus, ...