Information can be broadly defined as any pattern that can be recognized by some system (e.g., a living organism, an electronic system or a mechanical device) and/or that can influence the formation or transformation of other patterns.
The pattern can be in any of a wide variety of forms, for example spoken or printed words, temperatures, visual images, pain, radioactivity, DNA, the structure of a crystal, color, or electron flows. It can range from extremely simple single binary values (e.g., yes or no, or zero or one) to something so complex that only a few human minds can understand it (e.g., Einstein's theory of relativity).
Information is dependent upon, but generally unrelated to, the medium or media used to store or express it. For example, a mathematical formula or the epic of Gilgamesh1 can be encoded in a baked clay tablet2, printed in a book, stored in a semiconductor memory chip, or retained in a human mind. The definition of information makes no assumption about either its accuracy or any direct communication between the pattern and the object or system perceiving or using it.
Living organisms are born with information encoded in their genes and, to varying extents, already in their brains. Additional information is then obtained through sensory inputs and through the exchange of genes with other organisms3. When a living organism receives information through a sensory organ, it transforms the input into a series of electrical and chemical signals that can result in the storage or use of that information.
The question arises as to whether patterns are information if they are not perceived by or do not affect any living organism or other system. A sensible response is that anything that has the potential to be perceived by or to affect a system can be regarded as information. There is no need for a conscious mind to comprehend, or even be aware of, the pattern. For example, DNA is a pattern that influences the formation and development of organisms without any need for conscious minds (although it can certainly affect conscious minds).
There has been a trend in physics to define the physical world as consisting of information itself. This is because of the prevailing view that everything in the universe is ultimately just a pattern of a few types of fundamental particles and/or of vibrations. These patterns (i.e., information) determine the realities as perceived by humans and other organisms.
A narrower, but more immediately useful, definition of information is a message that is communicated from a sender to a receiver. This is in contrast to noise, which can be defined as something that distorts or inhibits the flow of information. Along with assuming the existence of both a sender and a receiver, this definition ignores the idea of information as being something that can be extracted from an environment (e.g., through observation or measurement), and there is no assumption about the accuracy of the message.
This concept of information as being a message came to the forefront following the 1948 publication of a paper entitled A Mathematical Theory of Communication by Claude Shannon, a researcher at the legendary Bell Labs. This seminal work added a quantitative aspect to the understanding of information and provided the starting point for the development of modern information theory. Information theory is a mainly mathematical discipline that is concerned with the amount of information and the accuracy of its transmission. It has wide ranging applications, particularly in such fields as cryptography, data compression, linguistics and telecommunications.
Computers and information are intimately related. In fact, computer science is essentially just the study of the storage, transformation and transfer of information. Also, computers obviously greatly increase the ease of dealing with information, including accessing, copying and communicating it, and they are particularly adept at presenting it in visual and audio forms4.
The issuing of a command to a computer via a user interface (which now typically includes a keyboard, mouse and display device) is providing it with information. The information consists of the name of one or more programs to run along with any options and arguments (i.e., input data) for them. Computers also obtain information from other sources, including storage (e.g., disks and magnetic tape), other computers via networks, and various types of sensors (e.g., scanners, cameras and microphones).
The amount of information available to humans has been increasing at an ever-faster rate in recent centuries, and particularly during the last several decades, and thus terms such as the information age and the information society have come into widespread use. This acceleration is the result of (1) the growing world population and the increasing number of people and organizations involved in creating and processing information (e.g., writers, universities and dedicated research facilities) and (2) rapid advances in the technology for processing, storing and communicating information, particularly computers and telecommunications. Fortunately, such advances can also help make it easier for humans to cope with this information explosion.
Knowledge is a word that is often associated with information. It can be defined as the possession of information in the mind of a person, or collectively by a society, that has been gained through experience or studying. It could additionally include an appreciation of the relationships among numerous small units of information which by themselves are of lesser utility.
Documentation is any communicable material (such as text, video, audio, etc., or a combination thereof) that is used to explain some attributes of a man-made object, system or procedure, particularly its assembly, installation, maintenance, repair and disposal. Information, however, is a much more inclusive concept and can be about not just a product (i.e., a good or service), but about any topic. When information is about a product, it can cover every aspect of it, in addition to those covered by documentation, including its historical, political, philosophical, scientific, sociological, business, economic and environmental aspects.
Information can be costly to produce, process, store and distribute. And it is increasingly being treated as a commodity that is bought and sold in competitive markets like other goods and services rather than being hoarded by a priestly class (as was common throughout much of human history) or given away for free. In fact, it has become one of the world's largest industries5.
Although information cost is often defined as the cost of acquiring information about prices, quantities and qualities of products (including inputs to produce them, in the case of manufacturers), it can also be interpreted more broadly to include the costs of information that falls into the category of documentation. Reducing these costs can clearly benefit consumers and producers by allowing them to obtain the best values in their purchases and by making products easier to use. One of the greatest advances in recent years in reducing information costs has been the development of the Internet.
Information science is primarily a type of applied engineering that is concerned with the structure, creation, management, storage, retrieval and transfer of information, particularly with regard to large organizations. It can be considered as a more immediately practical offshoot of the results of computer science, which is a more theoretical discipline.
2Interestingly, baked clay tablets are one of the oldest but also one of the most durable media for storing information. Tablets discovered to date in Mesopotamia date back at least six thousand years, and such tablets have a theoretical durability far longer than that. It is not known whether today's digital media will be able to retain the information recorded in them for more than just a few decades.
3The exchange of genes between organisms, including those of very different species, was confirmed in 1931 by Harriet Creighton (1909-2004) and Barbara McClintock (1902-1992) in what was proclaimed one of the greatest experiments in biology. Moreover, it has been determined to be a very common phenomenon, and one that plays an important role in the ecosystem and possibly in evolution as well. It is made possible by viruses and other parasites.
4To a limited extent they can also provide information in other forms, such as tactile and temperature (e.g., through the use of devices that can create topologies with an array of movable pins that can be touched by humans). They are not yet proficient at providing information that is directly acquired through the sense of smell or taste.
5The size of the information industry could be considered in very rough terms as being the aggregate of the publishing, broadcasting, software, education and research industries.
Created December 12, 2005.