Incorrect effects This type of coincidence is common in computer systems where the user is running several applications. Cultural constraints Constraints which have evolved through artificial conventions that govern acceptable social behavior. These cultural conventions, of course, have to be learned, but once learned apply to a wide variety of circumstances. The mental model of a device is formed by the interpretation of its perceived actions and its visible structure. Upon seeing an object or a device, the user form a mental model of how the device or object operates.
Users use the model to simulate the operation of a device or object.
The visible structure of an object. Conceptual Models for Computers Computers are much more complex than physical objects. As a general purpose machine, a computer does not have a conceptual model. Computers are used for many different purposes and run many different applications. No one conceptual model is possible.