To create Linked Open Data (LOD) it is possible to link data entered into the database with a Reference System. Online available controlled vocabularies and gazetteers are particularly suitable for this. But it is also possible to link your own data with analog resources, e.g. card catalogs or inventory data from museums.
Wikidata and GeoNames are available in OpenAtlas by default but other applications can be added by the users. To see which reference systems are already available on your OpenAtlas instance, click the Reference system button on the start page.
Please note: As for types, different user groups have different permissions regarding the creation and modification of external reference systems. To add or edit an external reference you have to have the role of admin or manager. Further information can be found in the manual entry regarding Reference System and under User.
Create a new reference system¶
To create a new reference system click the Reference System button on the starting page of your OpenAtlas instance. You will then see a list with all already added external references. If permissions to create additional external references are available, a +Reference system button can also be found here. Click it to get into the form. Here you can fill in the following fields:
Name: Choose a descriptive name; as for other forms, a name is required to save data.
Website URL: State the vocabulary’s/gazetteer’s URL, e.g. https://www.wikidata.org for Wikidata
Resolver URL: Put in an URL that brings you to the respective entry when combined with an ID e.g. https://www.wikidata.org/wiki/ see for example https://www.wikidata.org/wiki/Q3044 where Q3044 is an ID (the link will bring you directly to Charlemagne’s entry in Wikidata)
Example ID: An example ID can be specified, which is then used as an example in the corresponding input field of the different forms; for Wikidata this could be Q3044 (for Charlemagne), for Geonames for example 2761369 (for Vienna (AT))
External reference match: Here you can state a default precision (exact match or close match) that will be shown in the respective form; if you set a default reference match, the other(s) can be chosen from a drop down list if necessary, if no external reference match is set, it will be left blank and exact or close match can be chosen from a drop down list. Close match and exact match are SKOS based definitions of confidence
choose Close match if the data base entry and the entity in the vocabulary are sufficiently similar and can be used interchangeably in some information retrieval application (think a D-shaped belt buckle is a close match to a belt buckle (Wikidata ID Q3180027) or the historic Vienna is a close match to today’s Vienna as it is included in Geonames)
choose Exact match if there is a high degree of confidence that the entered data and the vocabulary’s entity are interchangeable (think Charlemagne - the King of Franks, King of Lombards and became Holy Roman Emperor in 800 AD is an exact match to Q3044 in Wikidata or the Venus of Willendorf in the Natural History Museum Vienna is an exact match to the entity Q131397 (Venus of Willendorf) in Wikidata)
Classes: Select here in which forms the new external reference should be displayed. This can appear in one or more forms
Description: you can add a description as free text if desired
Save the information to the database by clicking the Insert button.
Please keep in mind: When information is entered into a reference system field in a form, the data in this form can only be saved if an external reference match is also specified.