This article includes a list of general references, but it lacks sufficient corresponding inline citations. (June 2009) |
Relevance is the connection between topics that makes one useful for dealing with the other. Relevance is studied in many different fields, including cognitive science, logic, and library and information science. Epistemology studies it in general, and different theories of knowledge have different implications for what is considered relevant.
Definition
"Something (A) is relevant to a task (T) if it increases the likelihood of accomplishing the goal (G), which is implied by T."
A thing might be relevant, a document or a piece of information may be relevant. Relevance does not depend on whether we speak of "things" or "information".
Epistemology
If you believe that schizophrenia is caused by bad communication between mother and child, then family interaction studies become relevant. If, on the other hand, you subscribe to a genetic theory of relevance then the study of genes becomes relevant. If you subscribe to the epistemology of empiricism, then only intersubjectively controlled observations are relevant. If, on the other hand, you subscribe to feminist epistemology, then the sex of the observer becomes relevant.
Logic
In formal reasoning, relevance has proved an important but elusive concept. It is important because the solution of any problem requires the prior identification of the relevant elements from which a solution can be constructed. It is elusive, because the meaning of relevance appears to be difficult or impossible to capture within conventional logical systems. The obvious suggestion that q is relevant to p if q is implied by p breaks down because under standard definitions of material implication, a false proposition implies all other propositions. However though 'iron is a metal' may be implied by 'cats lay eggs' it doesn't seem to be relevant to it the way in which 'cats are mammals' and 'mammals give birth to living young' are relevant to each other. If one states "I love ice cream", and another person responds "I have a friend named Brad Cook", then these statements are not relevant. However, if one states "I love ice cream", and another person responds "I have a friend named Brad Cook who also likes ice cream", this statement now becomes relevant because it relates to the first person's idea.
Another proposal defines relevance or, more accurately, irrelevance information-theoretically. It is easiest to state in terms of variables, which might reflect the values of measurable hypotheses or observation statements. The conditional entropy of an observation variable e conditioned on a variable h characterizing alternative hypotheses provides a measure of the irrelevance of the observation variable e to the set of competing hypotheses characterized by h. It is useful combined with measures of the information content of the variable e in terms of its entropy. One can then subtract the content of e that is irrelevant to h (given by its conditional entropy conditioned on h) from the total information content of e (given by its entropy) to calculate the amount of information the variable e contains about the set of hypotheses characterized by h. Relevance (via the concept of irrelevance) and information content then characterize the observation variable and can be used to measure its sensitivity and specificity (respectively) as a test for alternative hypotheses.
More recently a number of theorists[who?] have sought to account for relevance in terms of "possible world logics" in intensional logic. Roughly, the idea is that necessary truths are true in all possible worlds, contradictions (logical falsehoods) are true in no possible worlds, and contingent propositions can be ordered in terms of the number of possible worlds in which they are true. Relevance is argued to depend upon the "remoteness relationship" between an actual world in which relevance is being evaluated and the set of possible worlds within which it is true.
Application
Cognitive science and pragmatics
In 1986, Dan Sperber and Deirdre Wilson drew attention to the central importance of relevance decisions in reasoning and communication. They proposed an account of the process of inferring relevant information from any given utterance. To do this work, they used what they called the "Principle of Relevance": namely, the position that any utterance addressed to someone automatically conveys the presumption of its own optimal relevance. The central idea of Sperber and Wilson's theory is that all utterances are encountered in some context, and the correct interpretation of a particular utterance is the one that allows most new implications to be made in that context on the basis of the least amount of information necessary to convey it. For Sperber and Wilson, relevance is conceived as relative or subjective, as it depends upon the state of knowledge of a hearer when they encounter an utterance.
Sperber and Wilson stress that this theory is not intended to account for every intuitive application of the English word "relevance". Relevance, as a technical term, is restricted to relationships between utterances and interpretations, and so the theory cannot account for intuitions such as the one that relevance relationships obtain in problems involving physical objects. If a plumber needs to fix a leaky faucet, for example, some objects and tools are relevant (e.g. a wrench) and others are not (e.g. a waffle iron). And, moreover, the latter seems to be irrelevant in a manner which does not depend upon the plumber's knowledge, or the utterances used to describe the problem.
A theory of relevance that seems to be more readily applicable to such instances of physical problem solving has been suggested by Gorayska and Lindsay in a series of articles published during the 1990s. The key feature of their theory is the idea that relevance is goal-dependent. An item (e.g., an utterance or object) is relevant to a goal if and only if it can be an essential element of some plan capable of achieving the desired goal. This theory embraces both propositional reasoning and the problem-solving activities of people such as plumbers, and defines relevance in such a way that what is relevant is determined by the real world (because what plans will work is a matter of empirical fact) rather than the state of knowledge or belief of a particular problem solver.
Economics
The economist John Maynard Keynes saw the importance of defining relevance to the problem of calculating risk in economic decision-making. He suggested that the relevance of a piece of evidence, such as a true proposition, should be defined in terms of the changes it produces of estimations of the probability of future events. Specifically, Keynes proposed that new evidence e is irrelevant to a proposition x, given old evidence q, if and only if x/eq = x/q, otherwise, the proposition is relevant.
There are technical problems with this definition, for example, the relevance of a piece of evidence can be sensitive to the order in which other pieces of evidence are received.
Law
The meaning of "relevance" in U.S. law is reflected in Rule 401 of the Federal Rules of Evidence. That rule defines relevance as "having any tendency to make the existence of any fact that is of consequence to the determinations of the action more probable or less probable than it would be without the evidence". In other words, if a fact were to have no bearing on the truth or falsity of a conclusion, it would be legally irrelevant.
Library and information science
This field has considered when documents (or document representations) retrieved from databases are relevant or non-relevant. Given a conception of relevance, two measures have been applied: Precision and recall:
Recall = a : (a + c), where
- a is the number of retrieved, relevant documents,
- c is the number of non-retrieved, relevant documents (sometimes termed "silence").
Recall is thus an expression of how exhaustive a search for documents is.
Precision = a : (a + b), where
- a is the number of retrieved, relevant documents,
- b is the number of retrieved, non-relevant documents (often termed "noise").
Precision is thus a measure of the amount of noise in document-retrieval.
Relevance itself has in the literature often been based on what is termed "the system's view" and "the user's view". Hjørland (2010) criticize these two views and defends a "subject knowledge view of relevance".
Politics
During the 1960s, relevance became a fashionable buzzword, meaning roughly 'relevance to social concerns', such as racial equality, poverty, social justice, world hunger, world economic development, and so on. The implication was that some subjects, e.g., the study of medieval poetry and the practice of corporate law, were not worthwhile because they did not address pressing social issues.[citation needed]
See also
- Description – Text for clarification; one of four rhetorical modes
- Distraction – Process of diverting the attention of an individual or group
- Information-action ratio
- Information overload – Decision making with too much information
- Intention – Mental state representing commitment to perform an action
- Intuitionistic logic – Various systems of symbolic logic
- Kripke semantics – Formal semantics for non-classical logic systems
- Relevance theory – Theory of cognitive linguistics
- Salience (language) – Property of being noticeable or important
- Source criticism – Process of evaluating an information source
References
- Hjørland, B. & Sejer Christensen, F. (2002). Work tasks and socio-cognitive relevance: a specific example. Journal of the American Society for Information Science and Technology, 53(11), 960–965.
- Apgar, David (2006). Risk Intelligence. Cambridge, MA: Harvard Business Publishing.
- Gorayska B. & R. O. Lindsay (1993). The Roots of Relevance. Journal of Pragmatics 19, 301–323. Los Alamitos: IEEE Computer Society Press.
- Hjørland, Birger (2010). The foundation of the concept of relevance. Journal of the American Society for Information Science and Technology, 61(2), 217–237.
- Keynes, J. M. (1921). Treatise on Probability. London: MacMillan
- Lindsay, R. & Gorayska, B. (2002) Relevance, Goals and Cognitive Technology. International Journal of Cognitive Technology, 1, (2), 187–232
- Sperber, D. & D. Wilson (1986/1995) Relevance: Communication and Cognition. 2nd edition. Oxford: Blackwell.
- Sperber, D. & D. Wilson (1987). Précis of Relevance: Communication and Cognition. Behavioral and Brain Science, 10, 697–754.
- Sperber, D. & D. Wilson (2004). Relevance Theory. In Horn, L.R. & Ward, G. (eds.) 2004 The Handbook of Pragmatics. Oxford: Blackwell, 607–632. http://www.dan.sperber.fr/?p=93
- Zhang, X, H. (1993). A Goal-Based Relevance Model and its Application to Intelligent Systems. Ph.D. Thesis, Oxford Brookes University, Department of Mathematics and Computer Science, October, 1993.
External links
- Malcolm Gladwell – Blink – full show: TVOntario interview regarding "snap judgements" and Blink
This article includes a list of general references but it lacks sufficient corresponding inline citations Please help to improve this article by introducing more precise citations June 2009 Learn how and when to remove this message Relevance is the connection between topics that makes one useful for dealing with the other Relevance is studied in many different fields including cognitive science logic and library and information science Epistemology studies it in general and different theories of knowledge have different implications for what is considered relevant Definition Something A is relevant to a task T if it increases the likelihood of accomplishing the goal G which is implied by T A thing might be relevant a document or a piece of information may be relevant Relevance does not depend on whether we speak of things or information EpistemologyIf you believe that schizophrenia is caused by bad communication between mother and child then family interaction studies become relevant If on the other hand you subscribe to a genetic theory of relevance then the study of genes becomes relevant If you subscribe to the epistemology of empiricism then only intersubjectively controlled observations are relevant If on the other hand you subscribe to feminist epistemology then the sex of the observer becomes relevant LogicGraphic of relevance in digital ecosystems In formal reasoning relevance has proved an important but elusive concept It is important because the solution of any problem requires the prior identification of the relevant elements from which a solution can be constructed It is elusive because the meaning of relevance appears to be difficult or impossible to capture within conventional logical systems The obvious suggestion that q is relevant to p if q is implied by p breaks down because under standard definitions of material implication a false proposition implies all other propositions However though iron is a metal may be implied by cats lay eggs it doesn t seem to be relevant to it the way in which cats are mammals and mammals give birth to living young are relevant to each other If one states I love ice cream and another person responds I have a friend named Brad Cook then these statements are not relevant However if one states I love ice cream and another person responds I have a friend named Brad Cook who also likes ice cream this statement now becomes relevant because it relates to the first person s idea Another proposal defines relevance or more accurately irrelevance information theoretically It is easiest to state in terms of variables which might reflect the values of measurable hypotheses or observation statements The conditional entropy of an observation variable e conditioned on a variable h characterizing alternative hypotheses provides a measure of the irrelevance of the observation variable e to the set of competing hypotheses characterized by h It is useful combined with measures of the information content of the variable e in terms of its entropy One can then subtract the content of e that is irrelevant to h given by its conditional entropy conditioned on h from the total information content of e given by its entropy to calculate the amount of information the variable e contains about the set of hypotheses characterized by h Relevance via the concept of irrelevance and information content then characterize the observation variable and can be used to measure its sensitivity and specificity respectively as a test for alternative hypotheses More recently a number of theorists who have sought to account for relevance in terms of possible world logics in intensional logic Roughly the idea is that necessary truths are true in all possible worlds contradictions logical falsehoods are true in no possible worlds and contingent propositions can be ordered in terms of the number of possible worlds in which they are true Relevance is argued to depend upon the remoteness relationship between an actual world in which relevance is being evaluated and the set of possible worlds within which it is true ApplicationCognitive science and pragmatics In 1986 Dan Sperber and Deirdre Wilson drew attention to the central importance of relevance decisions in reasoning and communication They proposed an account of the process of inferring relevant information from any given utterance To do this work they used what they called the Principle of Relevance namely the position that any utterance addressed to someone automatically conveys the presumption of its own optimal relevance The central idea of Sperber and Wilson s theory is that all utterances are encountered in some context and the correct interpretation of a particular utterance is the one that allows most new implications to be made in that context on the basis of the least amount of information necessary to convey it For Sperber and Wilson relevance is conceived as relative or subjective as it depends upon the state of knowledge of a hearer when they encounter an utterance Sperber and Wilson stress that this theory is not intended to account for every intuitive application of the English word relevance Relevance as a technical term is restricted to relationships between utterances and interpretations and so the theory cannot account for intuitions such as the one that relevance relationships obtain in problems involving physical objects If a plumber needs to fix a leaky faucet for example some objects and tools are relevant e g a wrench and others are not e g a waffle iron And moreover the latter seems to be irrelevant in a manner which does not depend upon the plumber s knowledge or the utterances used to describe the problem A theory of relevance that seems to be more readily applicable to such instances of physical problem solving has been suggested by Gorayska and Lindsay in a series of articles published during the 1990s The key feature of their theory is the idea that relevance is goal dependent An item e g an utterance or object is relevant to a goal if and only if it can be an essential element of some plan capable of achieving the desired goal This theory embraces both propositional reasoning and the problem solving activities of people such as plumbers and defines relevance in such a way that what is relevant is determined by the real world because what plans will work is a matter of empirical fact rather than the state of knowledge or belief of a particular problem solver Economics The economist John Maynard Keynes saw the importance of defining relevance to the problem of calculating risk in economic decision making He suggested that the relevance of a piece of evidence such as a true proposition should be defined in terms of the changes it produces of estimations of the probability of future events Specifically Keynes proposed that new evidence e is irrelevant to a proposition x given old evidence q if and only if x eq x q otherwise the proposition is relevant There are technical problems with this definition for example the relevance of a piece of evidence can be sensitive to the order in which other pieces of evidence are received Law The meaning of relevance in U S law is reflected in Rule 401 of the Federal Rules of Evidence That rule defines relevance as having any tendency to make the existence of any fact that is of consequence to the determinations of the action more probable or less probable than it would be without the evidence In other words if a fact were to have no bearing on the truth or falsity of a conclusion it would be legally irrelevant Library and information science This field has considered when documents or document representations retrieved from databases are relevant or non relevant Given a conception of relevance two measures have been applied Precision and recall Recall a a c where a is the number of retrieved relevant documents c is the number of non retrieved relevant documents sometimes termed silence Recall is thus an expression of how exhaustive a search for documents is Precision a a b where a is the number of retrieved relevant documents b is the number of retrieved non relevant documents often termed noise Precision is thus a measure of the amount of noise in document retrieval Relevance itself has in the literature often been based on what is termed the system s view and the user s view Hjorland 2010 criticize these two views and defends a subject knowledge view of relevance Politics During the 1960s relevance became a fashionable buzzword meaning roughly relevance to social concerns such as racial equality poverty social justice world hunger world economic development and so on The implication was that some subjects e g the study of medieval poetry and the practice of corporate law were not worthwhile because they did not address pressing social issues citation needed See alsoDescription Text for clarification one of four rhetorical modes Distraction Process of diverting the attention of an individual or group Information action ratio Information overload Decision making with too much information Intention Mental state representing commitment to perform an action Intuitionistic logic Various systems of symbolic logic Kripke semantics Formal semantics for non classical logic systems Relevance theory Theory of cognitive linguistics Salience language Property of being noticeable or important Source criticism Process of evaluating an information sourceReferencesHjorland B amp Sejer Christensen F 2002 Work tasks and socio cognitive relevance a specific example Journal of the American Society for Information Science and Technology 53 11 960 965 Apgar David 2006 Risk Intelligence Cambridge MA Harvard Business Publishing Gorayska B amp R O Lindsay 1993 The Roots of Relevance Journal of Pragmatics 19 301 323 Los Alamitos IEEE Computer Society Press Hjorland Birger 2010 The foundation of the concept of relevance Journal of the American Society for Information Science and Technology 61 2 217 237 Keynes J M 1921 Treatise on Probability London MacMillan Lindsay R amp Gorayska B 2002 Relevance Goals and Cognitive Technology International Journal of Cognitive Technology 1 2 187 232 Sperber D amp D Wilson 1986 1995 Relevance Communication and Cognition 2nd edition Oxford Blackwell Sperber D amp D Wilson 1987 Precis of Relevance Communication and Cognition Behavioral and Brain Science 10 697 754 Sperber D amp D Wilson 2004 Relevance Theory In Horn L R amp Ward G eds 2004 The Handbook of Pragmatics Oxford Blackwell 607 632 http www dan sperber fr p 93 Zhang X H 1993 A Goal Based Relevance Model and its Application to Intelligent Systems Ph D Thesis Oxford Brookes University Department of Mathematics and Computer Science October 1993 External linksLook up relevance relevant or irrelevant in Wiktionary the free dictionary Wikiquote has quotations related to Relevance Malcolm Gladwell Blink full show TVOntario interview regarding snap judgements and Blink
