Updated: Apr 22
"The Jabberwocky". An illustration to the poem Jabberwocky. First published in Carroll, Lewis. 1871. Through the Looking-Glass, and What Alice Found There.
What is semantics?
Semantics is the branch of linguistics that studies the signified, that is, what we are talking about, what we want to communicate. For its part, syntax is interested in the signifier, i.e. the form of the statement: spelling, language, grammar, etc. There is the same relationship between semantics and syntax as between substance and form. Semantics has many objects of study, including:
The meaning of compound words;
The relations of meaning between words (homonyms, synonyms, antonyms, etc.)
The relations between words, for example polysemy (words with several meanings), hyperonymy (all-encompassing category, for example vehicle is the hyperonym of car, bicycle and ship); hyponymy (reverse hyperonymy relationship);
Pragmatic, that is, taking into account the context necessary to access the meaning of a text.
Interoperability requires stability
The big problem with interoperability, whatever the domain, but particularly for IoT, is that the parties must agree in advance. This is only possible if the object of the agreement is well defined and above all very stable: the duration of the agreement must be several orders of magnitude greater than the time necessary for its conclusion, under penalty of instability or even divergence. This is true for accounting rules, smartphone connectivity (reminds you of something?), the driving side, the choice of currency, the enactment of a law, the setting of a unit or the shape of traffic signs.
IoT and semantics go hand in hand
The Internet of Things is a very mobile field when viewed up close - but very stable from afar. It is no longer difficult or expensive to develop a new connected object; their number and variety continue to grow. Time to market is short. Restricting the creativity of the industry by imposing a rigid mold is illusory and counterproductive: Moore's law will quickly break it.
On the other hand, the actions that objects perform, the type of data they provide, are relatively limited: there can be a hundred types of connected thermometer, each with its specific interface, size, environmental characteristic, they will only provide the current temperature in '°C' or '°F'.
In other words, the role (meaning) of each object is defined and stable (semantics: providing a temperature), while the way in which information is measured and delivered is - and must remain - open and unconstrained: alone the semantic level can provide IoT with long-term interoperability allied to short-term freedom.