9. Dedicated kinds-of-property
A bare kind-of-property — length, volume fraction, substance concentration —
is generic: it names what is measured without saying of what. Dybkær's
Chapter 20 closes that gap with the dedicated kind-of-property, defined there as
"a kind-of-property with given sort of system and any pertinent component". It is
the syntax laboratory medicine already uses for a fully-specified measurand —
System — Component ; kind-of-property, as in "Plasma — Glucose ; substance
concentration", or, in this project's home domain, "Soil — Water ; volume
fraction" (volumetric water content). Note what the definition asks for: a
sort of system. Plasma and soil name sorts, and the catalogue entry is one
entry for every plasma sample and every soil sample there will ever be. The
particular system a measured value characterizes enters one layer down, as the
object index of an individual quantity — dedication to the sort, individuation by
the object.
This is the construct the QUDV → OML/OWL2 lineage cannot express. A description logic can record that a quantity has a sort of system and has a component, but it cannot make "Soil — Water ; volume fraction" and "Soil — Water ; mass fraction" provably distinct kinds while keeping both dedicated to the same sort and the same component. Here that distinctness is a theorem, and it is the principled form of the dimension-1 disambiguation: volumetric and gravimetric water content are the same measurement target — soil, water — examined as two different kinds-of-property, so they differ because the kinds-of-property differ, not because someone chose two different identity strings.