TCG defines the notion of trust as “the expectation that a device will behave in a particular manner for the specific purpose”. For example, it is the expectation that our kitchen refrigerator will cool its contents to the level specified by its thermostat, no more (interfering with the contents placed within, spying on users opening the door, borrowing electricity to transmit wireless messages) and no less (failing to cool during early morning hours, changing the thermostat settings unpredictably)
When a user contacts me with a software problem it's amazing how often they seem to blame the software. For example "CAN'T REACH" must be some sort of bug. The fact that the robot can't actually reach because of the coordinates specified somehow is not trusted. So many users have been acclimatized to Windows applications that fall over with great regularity that they expect rock solid embedded software like RoboForth to do the same.