STANDARDS DEFINITIONS CLASSICAL THESAURUS SEMANTIC RELATIONS TECHNICAL - METHODICAL THESAURUS EXAMPLE REFERENCES Standards: The structure of thesauri is controlled by international standards that are among the most influential ever developed for the library and information field. The main three standards define the relations to be used between terms:   ·     monolingual thesauri (ISO 2788:1986) ·     multilingual thesauri (ISO 5964:1985) ·     methods for examining documents, determining their subjects, and selecting index terms (ISO 5963:1985)   The general principles in ISO 2788 are considered language- and culture-independent. As a result, ISO 5964:1985, refers to ISO 2788 and uses it as a point of departure for dealing with the specific requirements that emerge when a single thesaurus attempts to express 'conceptual equivalencies' among terms selected from more than one natural language. The ISO standards for thesauri (ISO 2788 and ISO 5964:1985) are developed and maintained by the International Organization for Standardization, Technical Committee 46 whose remit is Information and Documentation. ISO 5964:1985 is currently undergoing review by ISO TC46/SC 9, and it is expected that among changes to it will be the inclusion of a standard interchange format for thesauri. To facilitate the growth of the Semantic Web, it would be sensible to try to ensure that such an interchange format is as compatible with Semantic Web ontology representations as possible.    Another standard is developed by the National Information Standards Association Organisation, approved 28 August 2003. guidelines for the construction, format and management of monolingual thesauri (ANSI/NISO Z 39.19:2003 ) Definitions: The vocabulary of a controlled indexing language, formally organized so that the a priori relationships between concepts (for example as 'broader' and 'narrower') are made explicit' (ISO 2788, 1986:2) A controlled set of terms selected from natural language and used to represent, in abstract form, the subjects of documents' (ISO 2788, 1986:2) A thesaurus is a controlled vocabulary arranged in a known order and structured so that equivalence, homographic, hierarchical, and associative relationships among terms are displayed clearly and identified by standardized relationship indicators that are employed reciprocally. The primary purposes of a thesaurus are (a) to facilitate retrieval of documents and (b) to achieve consistency in the indexing of written or otherwise recorded documents and other items, mainly for postcoordinate information storage and retrieval systems. This standard provides guidelines (ANSI/NISO Z 39.19:2003) What is in a Thesaurus: Preferred terms: the thesaurus indicates which terms the indexer or searcher is allowed to use. These terms are called the preferred terms. Those terms are marked as descriptors. Preferred terms serve as focal points where all the information about a concept is collected. None-preferred terms: the terms not allowed to be used in addition to the preferred terms. One of two or more synonyms or lexical variants that serves as an entry term. A thesaurus also usually allows you to look up a preferred term and see its non-preferred terms. This can give you a better idea of what the term is supposed to mean. For the EXAMPLE, all non-preffered terms were put into Italics. Non-preferred terms are included in a thesaurus mainly to help users find the appropriate preferred terms. Non-preferred terms may also help to define the scope of preferred terms. Semantic relations: links between different terms. Explain the relation of the meaning of a term. See describtion below. Guides to application: Guiding people in using a thesaurus can be accomplished by showing non-preffered terms and semantic relations. Rules for Synthesis: on the one hand enumerative (by the mean of indexing without hierarchical order) ® list all terms explicit. On the other hand synthetic ® instead of listing terms, develop rules for creating them out of components. Semantic Relations: narrower term; the term that follows the symbol refers to a concept with a more specific meaning (NT) broader term; the term that follows the symbol represents a concept having a wider meaning (BT). See the following example: 'Natural Hazards' is a broader term to term 'Landslides'(and term 'Landslides' is a narrower term to term 'Natural Hazards') if all the things included in the class named by the term 'Landslides' are included in the class named by the term 'Natural Hazards' On the other hand 'Debris flow' is not a Broader term to 'Mud flow' or 'Clay flow slides'. The three terms differ in their rheology and explain self contained processes use for; the term that follows the symbol is a non-preffered synonym or quasi-synonym (UF) the term that follows the symbol is the preffered term when a choice between synonyms or quasi-synonyms exists  (USE)           A non-preferred term is normally linked to a corresponding preferred term by a USE reference. The corresponding reference in the opposite direction is UF ('Used For') Relation between the term 'landslides' and 'lateral spreads'. Due to lateral spread is a non-preffered term, the semantic relation between both terms means: USE the term 'landslide' instead of 'lateral spread'. Accordingly the user is given the information that 'landslide' is Used For 'lateral spreads' general term (GT) whole term (WT) part term (PT) associated term (AT) related term; the term that follows the symbol is accociated, but is not a synonym, a quasi-synonym, a broader term or a narrower term (RT) synonym related term (SRT) used prefered term (USP) scope note; a note attached to a term to indicate its meaning within an indexing language (SN) top term; the term that follows the symbol is the name of the broadest class to which the specific concept belongs; sometimes used in the alphabetical section of a thesaurus (TT) can be expanded by language relations: language term (LT) subterms: english term (ELT) french term (FLT) german term (GLT) italian term (ILT) slovenian term (SLT)   Technical methodical thesaurus: The technical-methodical thesaurus defines the relationship between preferred terms (defined due to the classical thesaurus) and the practise of process documentation. The kind of relation is to be defined by experts on the basis of their experiences with natural hazard recordation and natural hazard presentation. The basics are technical reports, spatial and thematical attributes, different kind of maps (danger zoning, disaster rescue mapping,...) as well as recordation methods, documentations, presentations, research methods for outlining natural hazard processes, methods of risk-management, risk-prevention and risk-evaluation forms. etc.