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increasingly applied outside astronomy, in contexts in which the measurementindependent existence of properties (and their values) is more controversial, explanations of it became increasingly divorced from metaphysically realist foundations;
for example: “the true value [of the measurand] is the result that would be obtained
by a perfect measurement. Since perfect measurements are only imaginary, a true
value is always indeterminate and unknown” (Regtien, 2004: p. 44, emphasis
added). In a similar vein, the development of classical test theory (tellingly also
referred to as “True Score Theory”; Lord & Novick, 1968) drew upon the mathematics of the theory of errors but rejected the realist metaphysics, instead formally
defining the true score simply as the expected value of the raw score (which itself is,
usually, the number of items answered correctly or endorsed by a respondent out on
a given test or survey) over a (hypothetical) infinite series of replications of administration of the test under identical conditions. As noted by Denny Borsboom (2005),
while individual researchers might endorse realist interpretations of the true score
(for example, as referring to the value of an existing quantity that is measured by the
true score), its formal definition is more consistent with operationalism, as it is
defined with reference to a particular test.
As conceptions of measurement became increasingly disconnected from assumptions about the metaphysics of properties, the way was opened to non-realist philosophical perspectives on measurement, as discussed further in the following
sections.
4.2.2 Operationalist perspectives on measurement
In the early part of the twentieth century, as philosophical thinking was trending
away from the naïve forms of realism described in the previous section, philosophers who identified with the movement known as logical positivism synthesized
many ideas from classical empiricism along with then-current advances in the philosophy of language and mathematics. Logical positivism was associated with the
position that statements regarding unobservable (theoretical) entities should only be
considered meaningful if they could be linked to observations in a clear and consistent manner.
The positivists saw measurement as a privileged means to establish the truth or
falsehood of statements. From this perspective, the empirical sciences could delegate the responsibility of ascertaining the truth of their theories to measurement, as
exemplified by the epistemic significance assigned to so-called crucial experiments,
which typically rely on high-quality measurements. However, in contrast to the
The naïve realist stereotype: Measurement is analogous to a transmission process, which in the ideal case identically transfers the true value of the measurand to the measured value provided by the measuring instrument.
4.2 Characterizing measurement
increasingly applied outside astronomy, in contexts in which the measurementindependent existence of properties (and their values) is more controversial, explanations of it became increasingly divorced from metaphysically realist foundations;
for example: “the true value [of the measurand] is the result that would be obtained
by a perfect measurement. Since perfect measurements are only imaginary, a true
value is always indeterminate and unknown” (Regtien, 2004: p. 44, emphasis
added). In a similar vein, the development of classical test theory (tellingly also
referred to as “True Score Theory”; Lord & Novick, 1968) drew upon the mathematics of the theory of errors but rejected the realist metaphysics, instead formally
defining the true score simply as the expected value of the raw score (which itself is,
usually, the number of items answered correctly or endorsed by a respondent out on
a given test or survey) over a (hypothetical) infinite series of replications of administration of the test under identical conditions. As noted by Denny Borsboom (2005),
while individual researchers might endorse realist interpretations of the true score
(for example, as referring to the value of an existing quantity that is measured by the
true score), its formal definition is more consistent with operationalism, as it is
defined with reference to a particular test.
As conceptions of measurement became increasingly disconnected from assumptions about the metaphysics of properties, the way was opened to non-realist philosophical perspectives on measurement, as discussed further in the following
sections.
4.2.2 Operationalist perspectives on measurement
In the early part of the twentieth century, as philosophical thinking was trending
away from the naïve forms of realism described in the previous section, philosophers who identified with the movement known as logical positivism synthesized
many ideas from classical empiricism along with then-current advances in the philosophy of language and mathematics. Logical positivism was associated with the
position that statements regarding unobservable (theoretical) entities should only be
considered meaningful if they could be linked to observations in a clear and consistent manner.
The positivists saw measurement as a privileged means to establish the truth or
falsehood of statements. From this perspective, the empirical sciences could delegate the responsibility of ascertaining the truth of their theories to measurement, as
exemplified by the epistemic significance assigned to so-called crucial experiments,
which typically rely on high-quality measurements. However, in contrast to the
The naïve realist stereotype: Measurement is analogous to a transmission process, which in the ideal case identically transfers the true value of the measurand to the measured value provided by the measuring instrument.
4.2 Characterizing measurement