Jan 9, 2015 05:03 AM
http://plato.stanford.edu/entries/information-semantic/
EXCERPT: “I love information upon all subjects that come in my way, and especially upon those that are most important.” Thus boldly declares Euphranor, one of the defenders of Christian faith in Berkley's Alciphron. Evidently, information has been an object of philosophical desire for some time, well before the computer revolution, Internet or the dot.com pandemonium. Yet what does Euphranor love, exactly? What is information? The question has received many answers in different fields. Unsurprisingly, several surveys do not even converge on a single, unified definition of information.
Information is notoriously a polymorphic phenomenon and a polysemantic concept so, as an explicandum, it can be associated with several explanations, depending on the level of abstraction adopted and the cluster of requirements and desiderata orientating a theory. The reader may wish to keep this in mind while reading this entry, where some schematic simplifications and interpretative decisions will be inevitable. Claude E. Shannon, for one, was very cautious:
Thus, following Shannon, Weaver [1949] supported a tripartite analysis of information in terms of
(1) technical problems concerning the quantification of information and dealt with by Shannon's theory
(2) semantic problems relating to meaning and truth; and
(3) what he called “influential” problems concerning the impact and effectiveness of information on human behaviour, which he thought had to play an equally important role.
And these are only some early examples of the problems raised by any analysis of information.
Indeed, the plethora of different analyses can be confusing. Complaints about misunderstandings and misuses of the very idea of information are frequently expressed, even if to no apparent avail. Sayre [1976], for example, criticised the “laxity in use of the term ‘information’” in Armstrong [1968] (see now Armstrong [1993]) and in Dennett [1969] (see now Dennett [1986]), despite appreciating several other aspects of their work. More recently, Harms [1998] pointed out similar confusions in Chalmers [1996], who
In order to try to avoid similar pitfalls, this entry has been organised into four sections. Section 1 attempts to draw a map of the main senses in which one may speak of semantic information, and does so by relying on the analysis of the concept of data. Sometimes the several concepts of information organised in the map can be variously coupled together. This should not be taken as necessarily a sign of confusion, for in some philosophers it may be the result of an intentional bridging. The map is not exhaustive and it is there mainly in order to avoid some obvious pitfalls and to narrow the scope of this article, which otherwise could easily turn into a short version of the Encyclopedia Britannica. Its schematism is only a starting point for further research and the reader interested in knowing more may wish to consult Floridi [2011] and Adriaans and van Benthem [2008].
After this initial orientation, Section 2 provides a brief introduction to information theory, that is, to the mathematical theory of communication (MTC). MTC deserves a space of its own because it is the quantitative approach to the analysis of information that has been most influential among several philosophers. It provides the necessary background to understand several contemporary theories of semantic information, especially Bar-Hillel and Carnap [1953], Dretske [1981].
Section 3 analyses information as semantic content. Section 4 focuses entirely on the philosophical understanding of semantic information, what Euphranor really loves.
The reader must also be warned that an initial account of semantic information as meaningful data will be used as yardstick to outline other approaches. Unfortunately, even such a minimalist account is open to disagreement. In favour of this approach one may say that at least it is less controversial than others. Of course, a conceptual analysis must start somewhere. This often means adopting some working definition of the object under scrutiny. But it is not this commonplace that one needs to emphasize here. The difficulty is rather more daunting. Philosophical work on the concept of (semantic) information is still at that lamentable stage when disagreement affects even the way in which the problems themselves are provisionally phrased and framed. Nothing comparable to the well-polished nature of the Gettier problem is yet available, for example. So the “you are here” signal provided in this article might be placed elsewhere by other philosophers. The whole purpose is to put the concept of semantic information firmly on the philosophical map. Further adjustments will then become possible....
EXCERPT: “I love information upon all subjects that come in my way, and especially upon those that are most important.” Thus boldly declares Euphranor, one of the defenders of Christian faith in Berkley's Alciphron. Evidently, information has been an object of philosophical desire for some time, well before the computer revolution, Internet or the dot.com pandemonium. Yet what does Euphranor love, exactly? What is information? The question has received many answers in different fields. Unsurprisingly, several surveys do not even converge on a single, unified definition of information.
Information is notoriously a polymorphic phenomenon and a polysemantic concept so, as an explicandum, it can be associated with several explanations, depending on the level of abstraction adopted and the cluster of requirements and desiderata orientating a theory. The reader may wish to keep this in mind while reading this entry, where some schematic simplifications and interpretative decisions will be inevitable. Claude E. Shannon, for one, was very cautious:
Quote:The word ‘information’ has been given different meanings by various writers in the general field of information theory. It is likely that at least a number of these will prove sufficiently useful in certain applications to deserve further study and permanent recognition. It is hardly to be expected that a single concept of information would satisfactorily account for the numerous possible applications of this general field. (italics added). (Shannon [1993], p. 180)
Thus, following Shannon, Weaver [1949] supported a tripartite analysis of information in terms of
(1) technical problems concerning the quantification of information and dealt with by Shannon's theory
(2) semantic problems relating to meaning and truth; and
(3) what he called “influential” problems concerning the impact and effectiveness of information on human behaviour, which he thought had to play an equally important role.
And these are only some early examples of the problems raised by any analysis of information.
Indeed, the plethora of different analyses can be confusing. Complaints about misunderstandings and misuses of the very idea of information are frequently expressed, even if to no apparent avail. Sayre [1976], for example, criticised the “laxity in use of the term ‘information’” in Armstrong [1968] (see now Armstrong [1993]) and in Dennett [1969] (see now Dennett [1986]), despite appreciating several other aspects of their work. More recently, Harms [1998] pointed out similar confusions in Chalmers [1996], who
Quote:seems to think that the information theoretic notion of information [see section 3, my addition] is a matter of what possible states there are, and how they are related or structured […] rather than of how probabilities are distributed among them. (p. 480).
In order to try to avoid similar pitfalls, this entry has been organised into four sections. Section 1 attempts to draw a map of the main senses in which one may speak of semantic information, and does so by relying on the analysis of the concept of data. Sometimes the several concepts of information organised in the map can be variously coupled together. This should not be taken as necessarily a sign of confusion, for in some philosophers it may be the result of an intentional bridging. The map is not exhaustive and it is there mainly in order to avoid some obvious pitfalls and to narrow the scope of this article, which otherwise could easily turn into a short version of the Encyclopedia Britannica. Its schematism is only a starting point for further research and the reader interested in knowing more may wish to consult Floridi [2011] and Adriaans and van Benthem [2008].
After this initial orientation, Section 2 provides a brief introduction to information theory, that is, to the mathematical theory of communication (MTC). MTC deserves a space of its own because it is the quantitative approach to the analysis of information that has been most influential among several philosophers. It provides the necessary background to understand several contemporary theories of semantic information, especially Bar-Hillel and Carnap [1953], Dretske [1981].
Section 3 analyses information as semantic content. Section 4 focuses entirely on the philosophical understanding of semantic information, what Euphranor really loves.
The reader must also be warned that an initial account of semantic information as meaningful data will be used as yardstick to outline other approaches. Unfortunately, even such a minimalist account is open to disagreement. In favour of this approach one may say that at least it is less controversial than others. Of course, a conceptual analysis must start somewhere. This often means adopting some working definition of the object under scrutiny. But it is not this commonplace that one needs to emphasize here. The difficulty is rather more daunting. Philosophical work on the concept of (semantic) information is still at that lamentable stage when disagreement affects even the way in which the problems themselves are provisionally phrased and framed. Nothing comparable to the well-polished nature of the Gettier problem is yet available, for example. So the “you are here” signal provided in this article might be placed elsewhere by other philosophers. The whole purpose is to put the concept of semantic information firmly on the philosophical map. Further adjustments will then become possible....