Polythematic Structured Subject Heading System (PSH)
Polythematic Structured Subject Heading System (PSH) is as a tool to organize and search for documents by subject.
It is a set of subject headings which can be used to describe the document by subject. In its latest version (2.1) PSH is bilingual (Czech-English). Subject headings in both languages are interconnected. PSH contains over 13 500 subject headings and is divided into 44 thematic sections which have been prepared by experts in the respective disciplines in cooperation with librarians.
Each subject heading is included in a hierarchy of six (or - under special circumstances - seven) levels according to its semantic content and specificity. The whole system is a tree structure and it represents various concepts from the most general to the more specific ones.
Availability
Currently the subject heading system is available in MARC21 and SKOS (Simple Knowledge Organization System) format. To work with a previous TXT file it was used a dedicated software PSH Manager.
Where to find PSH
To get an idea of how the subject heading system looks like as a whole, please feel free to visit the following websites:
National Technical Library's on-line catalogue of books
website of the Czech Technical University in Prague
STM Portal´s on-line catalogue
PSH/SKOS is now availabe under the Creative Commons License CC BY-SA 3.0 Czech Republic (Attribution-ShareAlike 3.0). That means you are free to copy, distribute, display and perform the work and make derivative works, but you also must give the original author credit and if you alter, transform, or build upon this work, you may distribute the resulting work only under a licence identical to this one.
Libraries and other users can obtain PSH/SKOS for free.
History
1993 - work on the subject heading system started, these activities were supported by several grants provided by the Ministry of Culture of the Czech Republic and the Ministry of Education, Youth and Sports of the Czech Republic
1997 - in March PSH was distributed to all interested parties - libraries and commercial companies
2000 - PSH Version 1.3 was distributed
2000 - in April the State Technical Library received financial support from the Ministry of Culture of the Czech Republic to translate PSH into the English language. PSH Version 1.4 is therefore bilingual.
2001 - PSH Version 1.4 was distributed. Based on the decision of the Ministry of Culture of the Czech Republic, the subject heading system was offered to public libraries for free and to commercial companies for fee. It was provided as a TXT file in which the order of the subject headings indicated the hierarchical structure. Each row contained a subject heading in Czech and in English, both accompanied by relevant references. Modified freeware which could link Czech and English subject headings and offered search capabilities was a part of the package.
2002 - a special maintenance module for the subject heading system was commissioned by the State Technical Library from KP-Sys (a company producing automated library systems). Revision of PSH Version 1.4. began.
2005 - PSH Version 2.0 was completed but due to a number of shortcomings it was not distributed to users
2006 - large-scale corrections of PSH Version 2.0 took place and a new version (2.1) was introduced
2006 - in November PSH in its latest version (2.1) was implemented to Aleph, an automated library system currently used at the State Technical Library (note: "State Technical Library" has been renamed to "National Technical Library" in 2009)
