This section provides an introduction to the development of electronic Dictionaries-Taxonomies.

What is a Taxonomic Dictionary or Ontology

A Taxonomic Dictionary is some kind of dictionary in which the terms (lemma) have explicit relationships with other terms, whereas also the terms that are used in the textual definitions may be explicitly related to other terms. A Taxonomy is comparable to a Thesaurus, which traditionally is used in libraries for categorization and searching of books and documents. In a thesaurus the terms are related primarily by 'wider term - narrower term relations'. Taxonomies primarily contain 'subtype-supertype relations', also called 'specialization-generalization relations', which are a special kind of narrower term-wider term relations. The subtype concepts in a taxonomy inherit all relations and thus all knowledge and requirements from their supertype(s). This improves responses to queries and enable the application of logic reasoning.

The Gellish Taxonomic Dictionary makes a distinction between concepts and terms, because for many different terms (synonyms, abbreviations, codes, etc.) can be used to denote the same concept. Therefore the Gellish Taxonomic Dictionary each concept has a language independent unique identifier (UID) that represents the concept across the languages in the Gellish family of formal languages. Each UID is related to one or more alias terms and translations. The relations are then defined between the unique identifiers and not between the terms. This makes that the Gellish taxonomy is natural language independant and can be displayed in any language for which terms are available. Thus knowledge that is expressed in one language becomes available to any language.

The Gellish guidelines for developing taxonomies enable that that various domain taxonomic dictionaries can be integrated into one consistent whole, because they are made conform a consistent method, whereas they are expressed in a common language that is computer interpretable as well as system independent.

If the terms in the taxonomic-dictionary are also related to each other by other kinds of relations we the collection of expressions is called an ontology. These other relations are also inherited to subtypes in the taxonomy. An ontology such as Gellish includes modeled definitions (also called definition models) and relationships of various kinds between the concepts that appear in those definition models.

With this in mind, a taxonomy can be defined more precisely as follows:
A taxonomy is a collection of concepts that are arranged in a subtype-supertype hierarchy, whereas each concept may be denoted by one or more terms (names or phrases).

This enables that multiple terms can be used to search for a particular concept and that the relations between the concepts can be used to find other concepts, definitions and also other knowledge, requirements and information about the concepts as far as is made available. The Taxonomic Dictionary thus becomes a core access point for knowledge and information retrieval as well as for logic reasoning.

The latest version of the Gellish English Dictionary-Taxonomy can be licensed via the webshop. The 2008 version is free of charge available via the download area. It can be used as such, or can be used as a basis for developing proprietary extensions. It can also be used as part of the application of one of the Gellish Formal languages, such as Formal English, for which it is the dictionary.
Proprietary extensions typically will have the form of Domain specific Taxonomic Dictionaries, in which the top concepts should be selected from the Gellish Taxonomic Dictionary, especially the base ontology section.

Further guidelines on building high quality taxonomic dictionaries are gven in the wiki and in the book 'Semantic Information Modeling Methodology'