102,819
edits
Changes
From Nordan Symposia
Jump to navigationJump to searchCreated page with 'File:lighterstill.jpg From Middle English mesure, from Anglo-French, from Latin mensura, from mensus, past participle of metiri to measure; akin to Old English mǣth mea...'
[[File:lighterstill.jpg]]
From Middle [[English]] mesure, from Anglo-French, from Latin mensura, from mensus, past participle of metiri to measure; akin to Old English mǣth measure, Greek metron
* Date: 13th century
==Definitions==
*1 a (1) : an adequate or due portion (2) : a moderate degree; also : moderation, temperance (3) : a fixed or suitable limit : bounds <rich beyond measure>
:b : the [[dimensions]], capacity, or amount of something ascertained by measuring
:c : an estimate of what is to be expected (as of a [[person]] or situation)
:d (1) : a measured [[quantity]] (2) : amount, degree
*2 a : an instrument or utensil for measuring b (1) : a standard or unit of measurement — see weight table table (2) : a system of standard units of measure <metric measure>
*3 : the [[act]] or [[process]] of measuring
*4 a (1) : [[melody]], tune (2) : [[dance]]; especially : a slow and stately dance
:b : rhythmic [[structure]] or [[movement]] : cadence: as (1) : poetic rhythm measured by [[temporal]] [[quantity]] or accent; specifically : meter (2) : musical time
:c (1) : a grouping of a specified number of musical beats located between two consecutive vertical lines on a staff (2) : a metrical unit : foot
*5 : an exact divisor of a number
*6 : a basis or standard of comparison <[[wealth]] is not a measure of [[happiness]]>
*7 : a step planned or taken as a means to an end; specifically : a proposed legislative act
— for good measure : in addition to the minimum required : as an extra
==Description==
===Classical===
In the classical definition, which is standard throughout the [[physical sciences]], measurement is the determination or estimation of ratios of quantities. [[Quantity]] and measurement are mutually defined: quantitative attributes are those, which it is possible to measure, at least in principle. The classical concept of quantity can be traced back to John Wallis and Isaac Newton, and was foreshadowed in Euclid's Elements[1].
===Representational===
In the representational theory, measurement is defined as "the correlation of [[numbers]] with entities that are not numbers"[2]. The strongest form of representational theory is also known as additive conjoint measurement. In this form of representational theory, numbers are assigned based on correspondences or similarities between the [[structure]] of number systems and the structure of [[qualitative]] [[systems]]. A property is quantitative if such structural similarities can be established. In weaker forms of representational theory, such as that implicit within the work of Stanley Smith Stevens, numbers need only be assigned according to a rule.
The [[concept]] of measurement is often misunderstood as merely the assignment of a [[value]], but it is possible to assign a value in a way that is not a measurement in terms of the requirements of additive conjoint measurement. One may assign a value to a person's height, but unless it can be established that there is a correlation between measurements of height and empirical relations, it is not a measurement according to additive conjoint measurement theory. Likewise, computing and assigning [[arbitrary]] values, like the "book value" of an asset in accounting, is not a measurement because it does not satisfy the necessary criteria.
===]Information theory===
[[Information theory]] recognizes that all [[data]] are inexact and [[statistical]] in [[nature]]. Thus the definition of measurement is: "A set of observations that reduce uncertainty where the result is expressed as a [[quantity]]."[3]. This definition is implied in what scientists actually do when they measure something and report both the mean and statistics of the measurements. In practical terms, one begins with an initial guess as to the value of a quantity, and then, using various [[method]]s and instruments, reduces the uncertainty in the [[value]]. Note that in this view, unlike the positivist representational theory, all measurements are uncertain, so instead of assigning one value, a range of values is assigned to a measurement. This also implies that there is a [[continuum]] between estimation and measurement.
===Quantum mechanics===
In [[quantum mechanics]], a measurement is the "collapse of the wavefunction". The unambiguous meaning of the measurement problem is an unresolved fundamental problem in quantum mechanics.
==References==
# Michell, 1993
# Ernest Nagel: "Measurement", Erkenntnis, Volume 2, Number 1 / December, 1931, pp. 313-335, published by Springer, the Netherlands
# Douglas Hubbard: "How to Measure Anything", Wiley (2007), p. 21
==External links==
* [http://www.bipm.org/utils/common/documents/jcgm/JCGM_200_2008.pdf BIPM International Vocabulary of Measurement (VIM)]
* [http://www.nikon.com/about/feelnikon/universcale/ 'Universcale', an application showing the relative sizes of objects]
* [http://www.unc.edu/~rowlett/units/index.html A Dictionary of Units of Measurement]
* [http://www.minco.com/tools/unit-calculator.aspx?utm_source=Misc&utm_medium=redirect&utm_campaign=Misc Comprehensive Unit Conversion Calculator]
* [http://www.euramet.org/index.php?id=mis 'Metrology – in short' 3rd edition, July 2008 ISBN 978-87-988154-5-7]
[[Category: General Reference]]
From Middle [[English]] mesure, from Anglo-French, from Latin mensura, from mensus, past participle of metiri to measure; akin to Old English mǣth measure, Greek metron
* Date: 13th century
==Definitions==
*1 a (1) : an adequate or due portion (2) : a moderate degree; also : moderation, temperance (3) : a fixed or suitable limit : bounds <rich beyond measure>
:b : the [[dimensions]], capacity, or amount of something ascertained by measuring
:c : an estimate of what is to be expected (as of a [[person]] or situation)
:d (1) : a measured [[quantity]] (2) : amount, degree
*2 a : an instrument or utensil for measuring b (1) : a standard or unit of measurement — see weight table table (2) : a system of standard units of measure <metric measure>
*3 : the [[act]] or [[process]] of measuring
*4 a (1) : [[melody]], tune (2) : [[dance]]; especially : a slow and stately dance
:b : rhythmic [[structure]] or [[movement]] : cadence: as (1) : poetic rhythm measured by [[temporal]] [[quantity]] or accent; specifically : meter (2) : musical time
:c (1) : a grouping of a specified number of musical beats located between two consecutive vertical lines on a staff (2) : a metrical unit : foot
*5 : an exact divisor of a number
*6 : a basis or standard of comparison <[[wealth]] is not a measure of [[happiness]]>
*7 : a step planned or taken as a means to an end; specifically : a proposed legislative act
— for good measure : in addition to the minimum required : as an extra
==Description==
===Classical===
In the classical definition, which is standard throughout the [[physical sciences]], measurement is the determination or estimation of ratios of quantities. [[Quantity]] and measurement are mutually defined: quantitative attributes are those, which it is possible to measure, at least in principle. The classical concept of quantity can be traced back to John Wallis and Isaac Newton, and was foreshadowed in Euclid's Elements[1].
===Representational===
In the representational theory, measurement is defined as "the correlation of [[numbers]] with entities that are not numbers"[2]. The strongest form of representational theory is also known as additive conjoint measurement. In this form of representational theory, numbers are assigned based on correspondences or similarities between the [[structure]] of number systems and the structure of [[qualitative]] [[systems]]. A property is quantitative if such structural similarities can be established. In weaker forms of representational theory, such as that implicit within the work of Stanley Smith Stevens, numbers need only be assigned according to a rule.
The [[concept]] of measurement is often misunderstood as merely the assignment of a [[value]], but it is possible to assign a value in a way that is not a measurement in terms of the requirements of additive conjoint measurement. One may assign a value to a person's height, but unless it can be established that there is a correlation between measurements of height and empirical relations, it is not a measurement according to additive conjoint measurement theory. Likewise, computing and assigning [[arbitrary]] values, like the "book value" of an asset in accounting, is not a measurement because it does not satisfy the necessary criteria.
===]Information theory===
[[Information theory]] recognizes that all [[data]] are inexact and [[statistical]] in [[nature]]. Thus the definition of measurement is: "A set of observations that reduce uncertainty where the result is expressed as a [[quantity]]."[3]. This definition is implied in what scientists actually do when they measure something and report both the mean and statistics of the measurements. In practical terms, one begins with an initial guess as to the value of a quantity, and then, using various [[method]]s and instruments, reduces the uncertainty in the [[value]]. Note that in this view, unlike the positivist representational theory, all measurements are uncertain, so instead of assigning one value, a range of values is assigned to a measurement. This also implies that there is a [[continuum]] between estimation and measurement.
===Quantum mechanics===
In [[quantum mechanics]], a measurement is the "collapse of the wavefunction". The unambiguous meaning of the measurement problem is an unresolved fundamental problem in quantum mechanics.
==References==
# Michell, 1993
# Ernest Nagel: "Measurement", Erkenntnis, Volume 2, Number 1 / December, 1931, pp. 313-335, published by Springer, the Netherlands
# Douglas Hubbard: "How to Measure Anything", Wiley (2007), p. 21
==External links==
* [http://www.bipm.org/utils/common/documents/jcgm/JCGM_200_2008.pdf BIPM International Vocabulary of Measurement (VIM)]
* [http://www.nikon.com/about/feelnikon/universcale/ 'Universcale', an application showing the relative sizes of objects]
* [http://www.unc.edu/~rowlett/units/index.html A Dictionary of Units of Measurement]
* [http://www.minco.com/tools/unit-calculator.aspx?utm_source=Misc&utm_medium=redirect&utm_campaign=Misc Comprehensive Unit Conversion Calculator]
* [http://www.euramet.org/index.php?id=mis 'Metrology – in short' 3rd edition, July 2008 ISBN 978-87-988154-5-7]
[[Category: General Reference]]
