picking up the thread from last week on time periods -
We recently came across related issues in STAR when we wanted to search by time but found the representation of dates and periods in the data posed problems for semantic searching.
The STAR (Semantic Technologies for Archaeology resources) project aims to cross search different archaeological datasets and grey literature using the CIDOC CRM (plus English Heritage extension for archaeology) as an umbrella ontology framework and expressing controlled vocabularies in SKOS/RDF format.
Within the STAR datasets, archaeological entities are typically associated with a time span rather than an absolute date. These time spans are expressed in a variety of different textual forms e.g. centuries, AD/BC dates, named Roman Emperors / British Monarchs, 3 age system, etc. Thus we needed to convert the data to a more regular form and then align these time periods to a controlled set of known periods for search purposes (we also want to have start/end dates available).
So records containing date information were (semi-automatically) processed to give approximate lower and upper bounds of their time span. Then each record was assigned to a known time period identifier, via a measure of temporal closeness, which also yielded relationships of overlap/containment. As known time periods, we used the RCHME periods list, which is a fairly coarse grained list based on the three age system, and we also ran against the English Heritage "Timelines" thesaurus data, manually supplemented with start/end dates (based on scope notes and other information) for a more fine-grained controlled list of known periods.
This allows cross searching, either directly by absolute date, or by thesaurus concept. In the next stage, the data will be extracted to RDF, conforming to the CRM model for representing time period information (with periods represented by URIs).
For more information on what we did see description and examples at
http://hypermedia.research.glam.ac.uk/research_areas/kos/star/time-periods/ <http://hypermedia.research.glam.ac.uk/research_areas/kos/star/time-periods/>
along with details of the two period lists and the standalone application developed to assign a record to a controlled time period identifier.
It is possible to download and experiment with the application (.NET) if you are interested.
We'd be interested in any comments or suggestions.
Doug Tudhope and Ceri Binding
STAR Project http://hypermedia.research.glam.ac.uk/research_areas/kos/star/
Hypermedia Research Unit
Faculty of Advanced Technology
University of Glamorgan
Pontypridd CF37 1DL
http://hypermedia.research.glam.ac.uk/
________________________________
From: Museums Computer Group on behalf of Edmund Lee
Sent: Tue 06/10/2009 10:08
To: [log in to unmask]
Subject: Re: BC dates [Scanned]
Hello all,
MCG list members interested in another perspective on this issue may want to
have a look at the archive of the JISCmail discussion list FISH (Forum on
Information Standards in Heritage) which discussed a thesaurus of period
names in 2000.
The list is (I think) an open one so you should be able to find the message
archive from the JISCmail homepage (www.jiscmail.ac.uk) then call up the
archives for FISH and look at '00.
A fascinating topic... not sure about Eternity as a Top Term though: isn't
that 'outside of' time, or time-less? Would just 'Time' be the Top-term?
Best wishes
Edmund Lee
English Heritage
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