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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