Black box

As a black box is called in cybernetics and systems theory, a (possibly very complex ) system of which in the present context only the external behavior is to be considered. The internal structure may be known; Such knowledge must not be used (because a newer model may be built inside otherwise). It is limited in the investigation and description on the measurement of the input-output relations (EVA principle).

Unlike a closed system in thermodynamics such a system may also exchange matter with the environment, for example, a ticket vending machine.

The opposite of a black box is commonly referred to as White Box ( engl. white box ); the metaphorical terms consistent Glass box and clear box (german glass box or clear box ) are synonymous, but are used less frequently.

Word origin

The term Black Box (german black box ) originates from the military telecommunications and designated captured enemy unit that could not be opened because of the explosive charge may be contained therein.

Survey

In general, a black box an object whose internal structure and inner workings are unknown or are not as important considered. Of interest is rather only the behavior of the black box, which ensures a certain functionality via defined interfaces. The motivation for the use of the term does not tend to the interior interested (now), even if it sometimes in the sense of we know it ( anyway) is not used. This approach is often used to reduce the complexity of the observation object. The deliberate omission of detailed information ( depth information ) is also called information hiding. The system processor receives thereby an energy advantage, he can use it for other ( theoretical and practical ) issues.

In system theory, the black-box approach is used methodically, by merely changing the relationship between stimulus and response or input or output is analyzed for the analysis of system behavior. Causality is not assumed, but a simplifying assumption. Ideally, the mathematical description of these relationships allows conclusions on the substrate and the nature of the interconnections of signals within the system.

Application

Typical form of the black-box model is the modularization.

Successfully applied this method for electronic circuits, neural systems or individual neurons. The input stimuli analytically easily analyzable waveforms are chosen as sinusoidal signals, for example. As an intermediate stage of the analysis so-called equivalent circuits are constructed in which various electronic filters are the system behavior appropriately interconnected with each other. In addition, the method is in many numerical- mathematical method application.

Data encapsulation in programming and the Black- box testing in software development methods of software development.

From the perspective of organizational responsibility is spoken by a black box in order to clarify about that a maintenance technician is not responsible for certain internal function of a component - in case of failure it should only be replaced as a whole.

In the modeling of a mathematical model is referred to a black box, unless the internal behavior of a system to be taken into account in the modeling, only the response of a system is described in a mathematical formula.