Semantic Concepts: Concepts

Kees Woestenenk, 2012-07-19

Concepts are the base of our thinking and our language. Concepts are mental constructions structuring our consciousness. In the language a concept is recognized and identified by its name. A concept has meaning, more or less common for most people, within certain boundaries, and a certain language.

Mental construction

"Before there was earth or sea or the sky that covers everything, Nature appeared the same throughout the whole world: what we call chaos: a raw confused mass, nothing but inert matter, badly combined discordant atoms of things, confused in the one place" (Ovid, Metamorphoses). Without concepts there is Chaos, or All/Nothing or Fullness/Emptiness. A concept creates order, Chaos is divided into recognizable parts. Order only resides in our consciousness as mental constructions of the world around us as well as our internal world.
Amongst other things, order is created by Qualifications or Dimensions, such as the opposites (antonyms) : Light - Dark, Good - Bad, Yin - Yang, Life - Dead. The creation according to the book of Genesis started with the separation between Day and Night. A Dimension makes something measurable.
Another ordering is based on the distinction of shapes. A shape is imaginable by its Spatial dimensions. The Universe is shaped (even while its shape is hard to comprehend) , contrary to the unshaped, not imaginable Chaos. Some shapes refer to observations of the world outside our consciousness, like the Universe, a Cloud, a Tree, a Building construction, others exist in our mind only, such as a Plan or Project.
Besides Spatial dimensions there is a Time dimension: the Big Bang is an event from the past that started an ongoing movement, the story of genesis places events in a time order, a Life has a Begin and an End. We are conscious about Past and Future (the Present is where the Past transfers to the Future).

Concept and language

(see also SEP: Concepts and natural language) Concepts exist when they have a name, they are anchored in language. Language is the equipment for thinking and communication. The statement "Nice weather today" gives an opinion about the concept Weather, an opinion that has something to do with the concept, but that is not necessarily agreed with by somebody else. Thinking is speaking to yourself, the statement "I think thus I am" (Descartes) could also been phrased as "I speak thus I am" (linguistic determinism). Similar concepts appear in different languages, but a language might miss some concepts from other languages and sometimes they have a different meaning. Concepts may have more than one name (synonyms), and a name can be used for more than one concept (homonyms). For new concepts, new names are created: Car, Aircraft and Computer are relatively new concepts.
Language, however, is not restricted to concepts, it can also represent a reality of not conceptually bound events and facts. Hamlet of Shakespeare is a reality, not a concept. The fact that three times two makes six, is not a concept, neither is the fact that Obama has been elected as president of the United States. Hamlet and Obama, however, are both Persons, and Person is a concept, we call Hamlet and Obama instantiations of the concept Person, but it would be more correct saying that Person is a generalization of Hamlet and Obama (and others).

Concept and meaning

The theory of the Big Bang provides a possible description of the Universe, but long before the existence of this theory the Universe has been a concept that means something. Aristotle describes the cosmos as the 'earth' surrounded by 'aether' in which stars are floating. Even today there is different understanding, as shows from the conviction of creationists versus the evolutionary thinking.

The meaning of a concept is to a certain level universal and layed down in dictionaries. The dictionary also mentions synonyms, and with homonyms the different meanings, a thesaurus adds an hierarchical ordering to this with the terms 'narrower' and 'wider'. Yet, there might be quite a difference between the understanding of a concept in the mind of one person against the meaning of that concept in another person's mind, which leads to talking alongside each other, miscommunication. The concept itself has a clear meaning for these persons, but the commonality of the meaning varies.

Example: the term Construction has different meanings. The Construction of a sentence is a Grammatical construction, whereas the Construction of the Eiffel tower is understood as an assembly of steel bars and in mathematics the Construction of a triangle a method describes. Construction may also refer to either the activity of concetructing or the result of that activity (the finished work). In fact these are all different concepts, the term Construction is used for Grammatical construction, Building construction and Mathematical construction, and therefore is a homonym for different concepts.

SC Concepts

Concepts in Semantic Concepts (SC) are concepts as a philosophic notion as discussed above, but formally structured and defined, in order to make them unambigious, not only for humans but for computers as well. SC is a library of concepts, hence there is a hierarchichal ordering in SC starting with the concept Concept, which means that every item in SC is a concept, derived from Concept. Each concept is placed at a certain level in the hierarchy of concepts and each concept has set of names and a lexical as well as a formal definition (although at the the time of this writing many definitions are incomplete or even lacking). Many concepts also have references to external documents.

SC's structure is based on ISO 12006-3. For graphical representations see the ISO 12006-3 Class diagram and the IFD-NL Class Diagram.ISO 12006-3 does not provide guidelines for the content of libraries using the structure; for SC a set of Rules is developed and still under development at the the time of this writing.

Concept Names

A Name is a distinct Entity that can be assigned to a Concept. A Name is not necessarily unique for a single Concept, on the other hand a Concept can be indicated by more than one Name in a certain language, when this is the case then one Name is indicated as 'preferred'. Searching for a Name in SC may result in a list of Concepts carrying that Name, selecting one of them may get a Concept with a different preferred Name, or another type of Concept than the one that was intended. Names are only indications of Concepts, they are only there for human identification, the Concept itself is identified by a unique number, which is not very friendly for people, but effective for computers. So Names provide access to Concepts in a friendly way for humans, Concepts therefore carry Names that are common in natural - or technical - language.

Descriptions and Comments

A Concept may have several Descriptions. Descriptions are used as a kind of lexical definition, the formal definition is comprised of the set of defining attributes (discussed later for different Concept types). A Descripion is meant for human consumption.

A Description refers back to the Concept of which it is derived, adding facts that are specific for this Concept.

A Concept may have several Comments.

Usage

Under Usage Concepts are listed that use the current Concept in an assignment.

References

References refer to external documents that may help to better understand a Concept, or to provide access to related information. Links are provided for References that are accessible on the internet.

Illustrations

Illustrations are simple images that may help to understand a Concept. More extensive illustrations can be found in References (see above).

Administrative attributes

There is a number of Administrative attributes attached to a Concept:

  • ID: A number, unique for SC, identifying a Concept.
  • GUID: The globally unique identifier, identifying the Concept on the international platform (IFD/bSDD).
  • Type: The type of concept as defined in ISO 12006-3.
  • Version: A number, increased every time when the definition of the Concept changes.
  • Version date: The date of the latest change of the Concept. The date may change too for updates of the Concept that don't affect the definition.
  • Status: The status of the Concept definition, either 'DRAFT', 'CHECKED', 'APPROVED', 'INVALID' or 'TRANSFERRED'. The status 'TRANSFERRED' is used for Concepts that are merged, leaving the old Concept in place for existing links.
  • Owner: The organization responsible for the Concept definition

Supertypes and Subtypes

All Concepts are hierarchically grouped in a Specialization structure. A Specialization structure of Concepts is also referred to with the term Taxonomy. Specialization implies that a Supertype is a generalization of a Concept whereas a Subtype is a specialization of a Concept. A Concept is distinguished from its Supertype by additional Defining attributes, or by more limited Value domains of the Defining attributes, or by replacing an attribute by one of its Subtypes. Specialization is sometimes referred to as an [is a] relation, e.g. an Internal door [is a] Door. Specialization can be compared with Generalists and Specialists: a Generalist is somebody who knows nothing about everything whereas a Specialist is somebody who knows everything of nothing.

Formally Specialization implies that the Defining attributes of a Concept are also Defining attributes of the derived Subtypes. This is also indicated with the term Inheritance: a Subtype inherits the Defining attributes of a Concept, such as a human being inherits the genes of his or her parents. If the attribute is a quantifiable property then the value domain of that property is determined. A Subtype may narrow the value domain, but cannot broaden it, a narrowed value domain is then passed to Concepts that are derived from the Subtype. An inherited attribute may be replaced by a Concept that is a Subtype of that attribute. If, for example, a Distance is measured with a Length measure, then the Length measure could be replaced by a Length measure with the Unit metre, or the Length measure with the Unit inch.

Many specialization structures (Taxonomies) are so structured that a Concept can only have one Supertype; SC on the other hand has a Specialization structure allowing for multiple Supertypes. An Internal sliding door, for example, is a Subtype of Internal door as well as a Subtype of Sliding door. A Concept having multiple Supertypes inherits the Defining attributes of all of its Supertypes, attributes of the same type are combined, including their value domains.

The number of specialization levels is unlimited. Each specialization step increases the number of possible instances of a Concept, each instance on the other hand, is also an instance of the Supertype of a Concept.

The specialization hierarchy of SC starts with the Concept Concept, wich then specializes in the follwoing Subtypes:

These Concepts have their own type of Definition, which are discussed on their own pages.