6
where we give an illustration of how the typical format of measurement in the
human sciences, in terms of sets of items, can be seen as structurally analogous to
measurement approaches in the physical sciences.
1.2.1 A brief introduction to temperature and its measurement
While discussing the features and the problems of measurement systems in this
book we mention some examples of physical properties, including the well-known
cases of length and mass. In particular, in Chap. 6 the hypothesis that length is an
additive quantity is exploited in the construction that starts from lengths of rods, and
then leads to units of length and, hence, values of length. But a bit more is developed
for the example of temperature, which is used in Chap. 6 for showing how values
may be obtained for a nonadditive quantity and also in Chap. 7 where we introduce
a model of direct measurement.
From the perspective of our conceptual analysis of measurement, temperature
has some very interesting features. It is, first of all, a property of critical importance:
“Temperature has a profound influence upon living organisms. Animal life is normally feasible only within a narrow range of body temperatures, with the extremes
extending from about 0–5 °C (32–41 °F) to about 40–45 °C (104–113 °F).”
6
It is a
property that we perceive with our senses and that we understand qualitatively, in
relative terms of warmer and colder, but the quality of our perception system is quite
low, in particular due to its limited selectivity (what we actually perceive is the socalled apparent temperature, caused by the combined effects of air temperature,
relative humidity, and wind speed) and range (our thermoception loses all discriminatory power for temperatures outside the narrow range mentioned above). Given
its practical importance, it is not surprising that the history of the understanding and
the measurement of temperature is rich, with several significant stages (see, e.g.,
Chang, 2007; Sherry, 2011), from the starting point of our physiology, which allows
us to consider temperature only as a (partially) ordinal property based on the relation warmer than, to the introduction of instruments which make differences of
temperature observable by transducing temperature to the height of a liquid via the
effect of thermal expansion. Such instruments were based on the hypothesis of a
causal relation between temperature and volume: ceteris paribus, if the temperature
of the liquid increases then its volume increases (and then also its height increases,
thanks to the ingenious configuration of the instrument). In other words, the problem of the low sensitivity to temperature of the human senses was solved not by
looking for some sort of “temperature amplifier”, but by gaining and then exploiting
knowledge about the effects of temperature on a second property, which is in some
6 www.britannica.com/science/thermoreception.
1 Introduction
where we give an illustration of how the typical format of measurement in the
human sciences, in terms of sets of items, can be seen as structurally analogous to
measurement approaches in the physical sciences.
1.2.1 A brief introduction to temperature and its measurement
While discussing the features and the problems of measurement systems in this
book we mention some examples of physical properties, including the well-known
cases of length and mass. In particular, in Chap. 6 the hypothesis that length is an
additive quantity is exploited in the construction that starts from lengths of rods, and
then leads to units of length and, hence, values of length. But a bit more is developed
for the example of temperature, which is used in Chap. 6 for showing how values
may be obtained for a nonadditive quantity and also in Chap. 7 where we introduce
a model of direct measurement.
From the perspective of our conceptual analysis of measurement, temperature
has some very interesting features. It is, first of all, a property of critical importance:
“Temperature has a profound influence upon living organisms. Animal life is normally feasible only within a narrow range of body temperatures, with the extremes
extending from about 0–5 °C (32–41 °F) to about 40–45 °C (104–113 °F).”
6
It is a
property that we perceive with our senses and that we understand qualitatively, in
relative terms of warmer and colder, but the quality of our perception system is quite
low, in particular due to its limited selectivity (what we actually perceive is the socalled apparent temperature, caused by the combined effects of air temperature,
relative humidity, and wind speed) and range (our thermoception loses all discriminatory power for temperatures outside the narrow range mentioned above). Given
its practical importance, it is not surprising that the history of the understanding and
the measurement of temperature is rich, with several significant stages (see, e.g.,
Chang, 2007; Sherry, 2011), from the starting point of our physiology, which allows
us to consider temperature only as a (partially) ordinal property based on the relation warmer than, to the introduction of instruments which make differences of
temperature observable by transducing temperature to the height of a liquid via the
effect of thermal expansion. Such instruments were based on the hypothesis of a
causal relation between temperature and volume: ceteris paribus, if the temperature
of the liquid increases then its volume increases (and then also its height increases,
thanks to the ingenious configuration of the instrument). In other words, the problem of the low sensitivity to temperature of the human senses was solved not by
looking for some sort of “temperature amplifier”, but by gaining and then exploiting
knowledge about the effects of temperature on a second property, which is in some
6 www.britannica.com/science/thermoreception.
1 Introduction