Ad hoc

"Ad hoc" is a Latin phrase which means "for this purpose". It generally signifies a solution designed for a specific problem or task, non-generalizable, and which cannot be adapted to other purposes.

Common examples are organizations, committees, and commissions created at the national or international level for a specific task; in other fields the term may refer, for example, to a tailor-made suit, a handcrafted network protocol, or a purpose-specific equation. Ad hoc can also have connotations of a makeshift solution, inadequate planning, or improvised events. Other derivates of the Latin include AdHoc, adhoc and ad-hoc.

"Ad hoc" committee, commission or organization

An ad hoc organization, to include committees, are used when an objective needs consideration and no standing organ/committee within said organization can absorb that issue into its scope. Usually these committees are used on a temporary basis, such as temporary oversight of an issue, or review of the standing rules or the constitution of that organization.

"Ad hoc" computer network

Ad hoc The connection is established for the duration of one session and requires no base station. Instead, devices discover others within range to form a network for those computers. Devices may search for target nodes that are out of range by flooding the network with broadcasts that are forwarded by each node. Connections are possible over multiple nodes (multihop ad hoc network). Routing protocols then provide stable connections even if nodes are moving around. Sony's PlayStation Portable uses ad hoc connections for wireless multiplayer gaming, as does the Nintendo DS (although Nintendo does not officially use the term).Technically, the Nintendo Game Boy used this method for linking up to each other in a wired (Game Link Cable) or wireless (Game Boy Color IR Port, Game Boy Advance Wireless Adapter) mode.

See IEEE 802.11, Bluetooth, or ultra-wide band. The alternative is infrastructure, with a base station that manages the network for its range. The theory behind ad hoc networks falls within the Distributed Transient Network-paradigm.

The term ad hoc network can also refer to an independent basic service set (IBSS).

Mobile "ad hoc" networks

New social networks can be constructed by the combination of computation, communication and reputation. Location awareness, p2p computing and wireless networking technologies make it possible to design ad hoc networks of mobile devices to support the social networks of the people who wear them - a so-called “smart mob”.

The organizing among people and their devices is done informally (hence "ad hoc"), abruptly (the way text messaging young people everywhere coordinates meetings after school). "Their ability to establish communication links among devices during face-to-face encounters can be used to facilitate, augment or even promote human social interactions" [Howard 2002, pp.169-171] .

"Ad hoc" hypothesis

In science and philosophy, "ad hoc" means the addition of extraneous hypotheses to a theory in order to save it from being falsified. "Ad hoc" hypotheses compensate for anomalies not anticipated by the theory in its unmodified form. Scientists are often skeptical of theories that rely on frequent, unsupported adjustments to sustain them. "Ad hoc" hypotheses are often characteristic of pseudoscientific subjects. [Carroll, Robert T. "Ad hoc hypothesis." "The Skeptic's Dictionary". 22 Jun. 2008 .] Much of scientific understanding relies on the modification of existing hypotheses or theories, but these modifications are distinguished from "ad hoc" hypotheses in that the anomalies being explained propose a new means of being falsified.

"Ad hoc" hypotheses are not necessarily incorrect, however. An interesting example of an apparently supported "ad hoc" hypothesis was Albert Einstein's addition of the cosmological constant to general relativity in order to allow a static universe. Although he later referred to it as his "greatest blunder", it has been found to correspond quite well to the theories of dark energy. [Texas A&M University. "Einstein's Biggest Blunder? Dark Energy May Be Consistent With Cosmological Constant." "ScienceDaily" 28 November 2007. 22 June 2008 .]

"Ad hoc" pronunciation

Many reference works employ "ad hoc" pronunciation schemas as a way of indicating how words are pronounced. These are especially popular in U.S. published works

External links

* [http://www.skepdic.com/adhoc.html "ad hoc hypothesis"] Robert Todd Carroll, "Skeptic's Dictionary"