3. TOOLS AND TECHNIQUES USED IN THE DOCUMENTATION OF HUMAN RIGHTS EVENTS Definition Descriptor: a term used to describe persons, organisations, events, objects or places in a general way. A descriptor places the item being described in a certain class. For example, descriptors of a person can be ' has pierced ears, scar on chin and tattoo on left arm' . Definition Free text: an entry in ordinary language, often lengthy and unstructured. An example of a free text field is one for the narration of what happened in an event. Definition Limited free text: a short description consisting of a few words or a phrase. Definition Codes: symbol(s) representing descriptors or identifiers. A code consists of alphabetical and/or numerical characters and symbols. Other possible entries are dates and numeric values, which are usually entered according to pre-defined rules. In using descriptors, it is best if these are chosen from a controlled vocabulary. Definition Controlled vocabulary is a limited set of descriptors or identifiers, where preferred terms have been chosen over other possible terms, for handling information by processors and users. Such a list should be as exhaustive as possible, and should be constructed so as to eliminate dilemmas in choosing the entries. For instance, if two terms are equivalent (e.g. death penalty and capital punishment), then only one of them should be used as a descriptor. An elaborate construction of a controlled vocabulary is called a thesaurus. Definition Thesaurus: unlike a simple list of indexing terms, a thesaurus is arranged by themes and topics, usually grouped hierarchically, i.e. with more specific subjects shown as subsets of more general ones. A thesaurus normally consists of a systematic part, in which the descriptors, or indexing terms, are arranged in systematic groups, and an alphabetical part that serves as an index to the thesaurus. The advantage of a thesaurus is that it allows to be far more consistent in indexing. The drawback is that to construct a good thesaurus is very time consuming and requires considerable technical as well as subject skills. Definition A Micro-thesaurus is a short thesaurus that consists of descriptors or identifiers meant for specific fields. Some types of identifiers can also be constructed into Micro-thesauri (e.g. geographical areas). HURIDOCS has compiled a number of Micro-thesauri, and assigned corresponding codes to the descriptors and identifiers they contain. The document Micro-thesauri: A Tool for Documenting Human Rights Violations (usually referred to as Micro-thesauri), contains the Micro-thesauri that are to be used for the Standard Formats on Events and for other HURIDOCS tools. 26