A necessary consideration in the development or expansion of courses incorporating techniques such as geographic information systems (GIS) is the establishment of the infrastructure to support such instruction. Planning for the practical application of knowledge involves the determination of hardware, software, data and personnel needs.
Continuity: the tendency to perceive things as simply as possible with a continuous pattern rather than with a complex, broken-up pattern o Contiguity: the tendency to perceive 2 things that happen close together in time as being related Rods and cones, which one is less or more light/color sensitive?
Concurrency is the tendency for things to happen at the same time in a system. Concurrency is a natural phenomenon, of course. In the real world, at any given time, many things are happening simultaneously. When we design software to monitor and control real-world systems, we must deal with this natural concurrency.