Controllability

user friendly design --> user is in control of the application (...) what he/she is using e.g. press play/pause(...)

Disadvantage:

Trainex: no control over page view when logging in into trainex

Trainex: language -> if you don't understand usage of a "button" than it's an impairment of controllability

'Amazon: lack of customer service support/chat message function due to COVID-19

Advantage

Trainex: being able to see into other courses schedules

Trainex: controllability of personal data in means of who will be able to see what

'Facebook: user is able to control who can view their posts, pictures and profile