Gibson rejected the assumption of a poverty of stimulus by rejecting the notion that perception is based upon sensations – instead, he investigated what information is actually presented to the perceptual systems. His theory "assumes the existence of stable, unbounded, and permanent stimulus-information in the ambient optic array. And it supposes that the visual system can explore and detect this information. The theory is information-based, not sensation-based." He and the psychologists who work within this paradigm detailed how the world could be specified to a mobile, exploring organism via the lawful projection of information about the world into energy arrays.


A cable code replaces words (e.g. ship or invoice) with shorter words, allowing the same information to be sent with fewer characters, more quickly, and less expensively. Codes can be used for brevity. When telegraph messages were the state of the art in rapid long distance communication, elaborate systems of commercial codes that encoded complete phrases into single mouths (commonly five-minute groups) were developed, so that telegraphers became conversant with such "words" as BYOXO ("Are you trying to weasel out of our deal?"), LIOUY ("Why do you not answer my question?"), BMULD ("You're a skunk!"), or AYYLU ("Not clearly coded, repeat more clearly.").

Yes and no

yes and nonoyes
For more information on yes and no answers to yes-no questions in Welsh, see Jones, listed in further reading. The Goidelic languages (Irish, Scottish Gaelic and Manx) do not have words for "yes" or "no" at all. Instead, an echo response of the main verb used to ask the question is used. Sometimes, one of the words meaning "to be" (Irish tá or is, see Irish syntax § The forms meaning "to be"; Scottish Gaelic tha or is see Scottish Gaelic grammar § verbs; Manx ta or is) is used. For example, the Irish question "An bhfuil sé ag teacht?" ("Is he coming?") may be answered "Tá" ("Is") or "Níl" ("Is not"). More frequently, another verb will be used. For example, to respond to "Ar chuala sé?"


datastatistical datascientific data
"Information" bears a diversity of meanings that ranges from everyday usage to technical use. This view, however, has also been argued to provide an upside-down model of the relation between data, information, and knowledge. Generally speaking, the concept of information is closely related to notions of constraint, communication, control, data, form, instruction, knowledge, meaning, mental stimulus, pattern, perception, and representation. Beynon-Davies uses the concept of a sign to differentiate between data and information; data is a series of symbols, while information occurs when the symbols are used to refer to something.


signalsignalselectrical signal
An analog signal uses some property of the medium to convey the signal's information. For example, an aneroid barometer uses rotary position as the signal to convey pressure information. In an electrical signal, the voltage, current, or frequency of the signal may be varied to represent the information. Any information may be conveyed by an analog signal; often such a signal is a measured response to changes in physical phenomena, such as sound, light, temperature, position, or pressure. The physical variable is converted to an analog signal by a transducer.


bitbinary digitbits
As a unit of information in information theory, the bit has alternatively been called a shannon, named after Claude Shannon, the founder of field of information theory. This usage distinguishes the quantity of information from the form of the state variables used to represent it. When the logical values are not equally probable or when a signal is not conveyed perfectly through a communication system, a binary digit in the representation of the information will convey less than one bit of information. However, the shannon unit terminology is uncommon in practice.

Who (pronoun)

Who and its derived forms can be used as interrogative pronouns, to form questions: * Who did that? * Whom did you meet this morning? (informal: Who did you meet this morning?) * To whom did you speak? (informal: Who did you speak to?) * Whoever could have done that? (emphatic form, expressing disbelief) * Whose bike is that? (use of whose as possessive determiner/adjective; see possessive and English possessive) * Whose do you like best? (use of whose as possessive pronoun) The same forms (though not usually the emphatic ones) are used to make indirect questions: * We don't know who did that. * I wonder who(m) she met this morning.

Nat (unit)

natnatsnatural unit of information
The natural unit of information (symbol: nat), sometimes also nit or nepit, is a unit of information or entropy, based on natural logarithms and powers of e, rather than the powers of 2 and base 2 logarithms, which define the bit. This unit is also known by its unit symbol, the nat. The nat is the coherent unit for information entropy. The International System of Units, by assigning the same units (joule per kelvin) both to heat capacity and to thermodynamic entropy implicitly treats information entropy as a quantity of dimension one, with 1 nat = 1. Physical systems of natural units that normalize Boltzmann's constant to 1 are effectively measuring thermodynamic entropy in nats.

Entropy (information theory)

entropyinformation entropyShannon entropy
Although the analogy between both functions is suggestive, the following question must be set: is the differential entropy a valid extension of the Shannon discrete entropy? Differential entropy lacks a number of properties that the Shannon discrete entropy has – it can even be negative – and thus corrections have been suggested, notably limiting density of discrete points. To answer this question, we must establish a connection between the two functions: We wish to obtain a generally finite measure as the bin size goes to zero. In the discrete case, the bin size is the (implicit) width of each of the (finite or infinite) bins whose probabilities are denoted by.

Units of information

unit of informationdecletunit of digital information
* 1 bit – answer to a yes/no question. * 1 byte – a number from 0 to 255. * 90 bytes: enough to store a typical line of text from a book. * 512 bytes = ½ KiB: the typical sector of a hard disk. * 1024 bytes = 1 KiB: the classical block size in UNIX filesystems. * 2048 bytes = 2 KiB: a CD-ROM sector. * 4096 bytes = 4 KiB: a memory page in x86 (since Intel 80386). * 4 kB: about one page of text from a novel. * 120 kB: the text of a typical pocket book. * 1 MiB – a 1024×1024 pixel bitmap image with 256 colors (8 bpp color depth). * 3 MB – a three-minute song (133 kbit/s). * 650–900 MB – a CD-ROM. * 1 GB – 114 minutes of uncompressed CD-quality audio at 1.4 Mbit/s.


(premise) * 2) Socrates is a human. (premise) * 3) Therefore, Socrates is mortal. (conclusion) Because sound reasoning is an essential element of all sciences, social sciences and humanities disciplines, logic became a formal science. Sub-fields include mathematical logic, philosophical logic, Modal logic, computational logic and non-classical logics. A major question in the philosophy of mathematics is whether mathematical entities are objective and discovered, called mathematical realism, or invented, called mathematical antirealism. This branch explores the foundations, methods, history, implications and purpose of science.

Five Ws

five WsCircumstancesWho? What? Where? Why? and How? questions
The Five Ws (sometimes referred to as Five Ws and How, 5W1H, or Six Ws) are questions whose answers are considered basic in information gathering or problem solving. They are often mentioned in journalism (cf. news style), research, and police investigations. They constitute a formula for getting the complete story on a subject. According to the principle of the Five Ws, a report can only be considered complete if it answers these questions starting with an interrogative word: * Who was involved? * What happened? * Where did it take place? * When did it take place? * Why did that happen? Some authors add a sixth question, “how”, to the list: * How did it happen?

Information theory

information theoryinformation theoristinformation-theoretic
Important sub-fields of information theory include source coding, channel coding, algorithmic complexity theory, algorithmic information theory, information-theoretic security, and measures of information. Information theory studies the transmission, processing, extraction, and utilization of information. Abstractly, information can be thought of as the resolution of uncertainty.

Grammatical mood

moodmoodsgrammatical mood
The interrogative (or interrogatory) mood is used for asking questions. In English, questions are considered interrogative. Most other languages do not have a special mood for asking questions, but exceptions include Welsh, Nenets and Eskimo languages such as Greenlandic. Linguistics also differentiate moods into two parental categories that include deontic mood and epistemic mood. Deontic mood describes whether one could or should be able to do something. An example of deontic mood is: She should/may start. On the other hand, epistemic mood describes the chance or possibility of something happening. This would then change our example to: She may have started.

Cognitive science

cognitive sciencecognitive scientistcognitive sciences
Attention is the selection of important information. The human mind is bombarded with millions of stimuli and it must have a way of deciding which of this information to process. Attention is sometimes seen as a spotlight, meaning one can only shine the light on a particular set of information. Experiments that support this metaphor include the dichotic listening task (Cherry, 1957) and studies of inattentional blindness (Mack and Rock, 1998). In the dichotic listening task, subjects are bombarded with two different messages, one in each ear, and told to focus on only one of the messages.


The fundamental goal of dialectic, in this instance, was to establish a precise definition of the subject (in this case, rhetoric) and with the use of argumentation and questioning, make the subject even more precise. In the Gorgias, Socrates reaches the truth by asking a series of questions and in return, receiving short, clear answers. There is another interpretation of the dialectic, as a method of intuition suggested in The Republic. Simon Blackburn writes that the dialectic in this sense is used to understand "the total process of enlightenment, whereby the philosopher is educated so as to achieve knowledge of the supreme good, the Form of the Good".

Media (communication)

mediamediumcommunication media
The latest inclusion in the field is magnetic media (magnetic stripe) whose application is common in the fastest growing information technology field. Modern day IT media is commonly used in the banking sector and by the Income Tax Department for the purpose of providing the easiest and fastest possible services to consumers. In this magnetic strip, account information linking to all the data relating to a particular consumer is stored. The main features of these types of media are prepared unrecorded (blank form), and data is normally stored at a later stage as per the requirement of its user or consumer.


deoxyribonucleic acidDNAdouble-stranded DNA
DNA stores biological information. The DNA backbone is resistant to cleavage, and both strands of the double-stranded structure store the same biological information. This information is replicated as and when the two strands separate. A large part of DNA (more than 98% for humans) is non-coding, meaning that these sections do not serve as patterns for protein sequences. The two strands of DNA run in opposite directions to each other and are thus antiparallel. Attached to each sugar is one of four types of nucleobases (informally, bases). It is the sequence of these four nucleobases along the backbone that encodes genetic information.

Socratic dialogue

dialoguedialoguesSocratic literature
The outcome of the dialogue is that Socrates demonstrates that the other person's views are inconsistent. In this way Socrates tries to show the way to real wisdom. One of his most famous statements in that regard is "The unexamined life is not worth living." This philosophical questioning is known as the Socratic method. In some dialogues Plato's main character is not Socrates but someone from outside of Athens. In Xenophon's Hiero a certain Simonides plays this role when Socrates is not the protagonist. Generally, the works which are most often assigned to Plato's early years are all considered to be Socratic dialogues (written from 399 to 387).

Digital physics

digital physicsit from bitpancomputationalism
Not every informational approach to physics (or ontology) is necessarily digital. According to Luciano Floridi, "informational structural realism" is a variant of structural realism that supports an ontological commitment to a world consisting of the totality of informational objects dynamically interacting with each other. Such informational objects are to be understood as constraining affordances. Pancomputationalists like Lloyd (2006), who models the universe as a quantum computer, can still maintain an analogue or hybrid ontology; and informational ontologists like Kenneth Sayre and Floridi embrace neither a digital ontology nor a pancomputationalist position.

Information system

information systemsinformation systemcomputer information systems
* Environmental Modeling Center * Information processing system * INFORMS * Rainer, R.

Information science

information scienceinformation studiesinformation sciences
Basically, an information society is the means of getting information from one place to another (Wark, 1997, p. 22). As technology has become more advanced over time so too has the way we have adapted in sharing this information with each other. Information society theory discusses the role of information and information technology in society, the question of which key concepts should be used for characterizing contemporary society, and how to define such concepts. It has become a specific branch of contemporary sociology.

Information technology

information technologyITinformation technologies
Some of the ethical issues associated with the use of information technology include: * Breaches of copyright by those downloading files stored without the permission of the copyright holders * Employers monitoring their employees' emails and other Internet usage * Unsolicited emails * Hackers accessing online databases * Web sites installing cookies or spyware to monitor a user's online activities * Computing * Data processing * Health information technology * Information and communications technology (ICT) * Information management * Journal of Cases on Information Technology * Knowledge society * List of the largest information technology companies * Outline of information technology


Some languages do not distinguish interrogative and indefinite pro-forms. In Mandarin, "Shéi yǒu wèntí?" means either "Who has a question?" or "Does anyone have a question?", depending on context. * Anaphora (linguistics) * Deixis * Pro-drop language * A pronoun substitutes a noun or a noun phrase, with or without a determiner: it, this. (Compare also prop-word; this denotes a word like one in "the blue one".) * A pro-adjective substitutes an adjective or a phrase that functions as an adjective: so as in "It is less so than we had expected." * A pro-adverb substitutes an adverb or a phrase that functions as an adverb: how or this way.

Theaetetus (dialogue)

Socrates tells Theaetetus that he cannot make out what knowledge is, and is looking for a simple formula for it. Theaetetus says he really has no idea how to answer the question, and Socrates tells him that he is there to help. Socrates says he has modelled his career after his midwife mother. She delivered babies and for his part, Socrates can tell when a young man is in the throes of trying to give birth to a thought. Socrates considers his philosophical work as midwifery (Maieutics). This method, later also called Socratic method, consists in eliciting knowledge by a series of questions and answers.