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THE TWOFOLD NATURE OF MEASUREMENT AS EMPIRICAL AND LINGUISTIC OPERATION
Luca Mari
Libero Istituto Universitario C.Cattaneo
C.so Matteotti 22,21053 Castellanza (Va) - Italy
email: lmari@liuc.it
ISPRS Commission VI, Working Group 3
KEY WORD: Foundations of Measurement, Measurement Theory, Linguistics and Measurement
ABSTRACT:
From the assumption that measurement is a means to set a bridge between the empirical and the linguistic worlds, the
nature of such a bridge is analyzed. The paper discusses the current instability of the relations that measurement
establishes between empirical world and linguistics, and suggests historical causes for it. The topic has been of main
importance in the scientific work of Mariano Cunietti.
1. MARIANO CUNIETTI AND HIS HERITAGE
As his last Ph.D. student, and the only one explicitly
involved in research about the foundations of
measurements, I have had a privileged perspective to
learn from Professor Mariano Cunietti about fundamental
metrology (a systematic, although mainly oriented to
didactic purposes, presentation of his standpoint is in
Cunietti, 1977). In the long and open discussions we had,
I have heard him often repeating one of the axioms he
had assumed for his work: "measurement is a means to
set a bridge between the empirical and the linguistic
worlds".
It is because of such a peculiarity that measurement
inherits some characteristics of both these world. From
the empirical world it derives the operational issues
related to the measuring instrumentation. From the
linguistic world it derives the conventionality of the
assignments representing the measurement results.
Aware of the wide attention devoted by metrologists (and
by himself in his whole career) to the empirical side of
measurement, Mariano Cunietti chose to dedicate a main
part of his last years of scientific work to explore the
linguistic influence on measurement. His approach to the
topic was unusual, maybe even non-orthodox, but - as he
was used to explain - “after such a long career I can afford
to seek some fun ...”.
2. THE "MEASUREMENT DAY"
It was far more than personal amusement: under the
reference of the keyword "epistemological foundations of
measurement" in the first '80 Mariano Cunietti was able to
imagine and organize the meeting of metrologists with
experts of logic, philosophy of science, philosophy of
language, statistics, psychology, in open-minded
discussions. In synthesis this has been the "Measurement
Day", a workshop that since then has been held each year
(Cunietti et.al., 1994).
Having worked in close contact with him, I know how
important Mariano Cunietti considered the Measurement
Day: he had conceived it as a true inter-disciplinary
laboratory, able to both generate and disseminate the new
ideas that the metrologists would have been able to
synthesize from their discussions with the invited experts.
In their nature of common ground of the Measurement
Day, the issues related to the epistemological foundations
of measurement can be effectively expressed in terms of
the topic of the present paper: "the twofold nature of
measurement as empirical and linguistic operation".
The theme is comprehensive and complex, and it is
impossible to propose here even a general outlook of it.
Instead, what is deemed to be its main current problem
will be discussed, related to the “stability” of the bridge set
between the empirical world and the language by means
of measurement.
3. THE EMPIRICAL WORLD ...
The traditional metrology and the common practice of
measurement are pervaded by a strong objectivism. Its
bases can be traced back to Galileo («the universe is
written in the language of mathematics») and Kepler («the
numbers are in the world»), and ultimately the
Pythagorean school («everything to which our knowledge
can gain access has a number in itself, since without it we
can neither understand nor know») (the metrological
relevance of these positions is analyzed in more detail in
Mari, 1997). Such a number is the "true value" of each
specific quantity, the target of each operation of
measurement of such a quantity. A failure in maintaining a
correct reference to this target, as becomes manifest in
the case of "dispersion of experimental data", is deemed
as an "error" of measurement.
Interestingly, even the rather traditional ISO International
vocabulary of basic and general terms in metrology (ISO,
1993) admits that the very concept of true value is in
principle unknowable, and therefore implicitly establishes
