The situation where individuals who share the diagnosis of a particular disorder do not share all symptoms in common. A heterogeneous disorder is one where people with the disorder can present with a variety of different symptoms.
The state of being composed of units of different kinds. These units may be elements of pattern in space or intervals in time (Kolasa and Rollo 1991) Heterogeneity may be deterministic, random, or chaotic. Each of these types has corresponding expressions in space and time (see Picture)
A typical enterprise information system today includes many types of computer technology, from PCs to mainframes. These include a wide variety of different operating systems, application software and in-house developed applications. EAI solves the complex problem of making a heterogeneous infrastructure more coherent.