Querying Cultural Heritage

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SPARQL queries for cultural heritage data in the CIDOC-CRM ontology with British Museum examples and exercises

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  • Querying Cultural Heritage DataCultural Heritage Data Dr. Barry Norton, Development Manager, ResearchSpace* * Funded by the Andrew W. Mellon Foundation * Hosted by the Curatorial Directorate, British Museum
  • Statements and Patterns For one edge in a graph: bm-obj:EOC3130 crm:P52_has_current_owner bm-id:the-british-museumbm-obj:EOC3130
  • Statements and Patterns For one edge in a graph: bm-obj:EOC3130 crm:P52_has_current_owner bm-id:the-british-museum We can declare/retrieve one (N)Triple: bm-obj:EOC3130
  • Statements and Patterns For one edge in a graph: bm-obj:EOC3130 crm:P52_has_current_owner bm-id:the-british-museum We can declare/retrieve one (N)Triple: Or write this in Turtle: bm-obj:EOC3130 @prefix crm: . @prefix bm-obj: . @prefix bm-id: . bm-obj:EOC3130 crm:P52_has_current_owner bm-id:the-british-museum .
  • Statements and Patterns For one edge in a graph: bm-obj:EOC3130 crm:P52_has_current_owner bm-id:the-british-museum We can write this in Turtle: And check for it in SPARQL: bm-obj:EOC3130 bm-obj:EOC3130 crm:P52_has_current_owner bm-id:the-british-museum . PREFIX crm: PREFIX bm-obj: PREFIX bm-id: ASK {bm-obj:EOC3130 crm:P52_has_current_owner bm-id:the-british-museum} true
  • Statements and Patterns For a set of edges: bm-obj:EOC3130 bm-id:the-british-museum crm:P51_has_former_or_current_owner ? We can do the work on the client: Or have the server do it by turning the triple into a triple pattern: crm:P51_has_former_or_current_owner ? bm-obj:EOC3130 crm:P51_has_former_or_current_owner ?owner
  • Exercise ? ? Questions: Why is the answer different? Who are the two (other) one-time owners?
  • Solutions & Exercises Why is the answer different? Reasoning, part of the work by the server (being a triplestore) means that if two things are related by crm:P52_has_current_owner then theyre related bythen theyre related by crm:P51_has_former_or_current_owner This is part of the work that the server (triplestore) can do for you Exercise: query for the (strictly) former owners ? ?
  • Solution 1/2 Using specific server functionality:
  • Solution 2/2 In pure SPARQL:
  • Solutions & Exercises Who are the two (other) one-time owners? Since people and institutions (and places) are ? ? Since people and institutions (and places) are treated as are concepts, the names of the former owners are attached using skos:prefLabel Exercise: if you didnt already, include the names in your query results
  • Solutions & Exercises If you didnt already, include the names in your query results: Question: Why are we back at two answers?
  • Answer Answer: Just as we can add triples together to make a graph in RDF, so we can add triple patterns together in SPARQL to make a graph pattern By default all triple patterns must be matched, By default all triple patterns must be matched, but we can use the OPTIONAL {} pattern to allow variation Exercise: Query for the owners and their names, if they exist* * N.B. this bug in the BM data will be fixed soon
  • Solution
  • Exercise Take a look here: Exercise: copy and run this query
  • CSV Exercise Type: Observe that one can now paste the query including line breaks*including line breaks* Type: * N.B. for now you should first replace the "s with 's and change the one occurrence of ecrm: with crm: - well fix this * N.B. currently the query needs to be simplified as the BBC data is not loaded this will be available soon
  • Data Analysis One can import this CSV file into many tools: A spreadsheet can be a good way to carry out basic visualisations A scripting environment like (i)python/scipy or R can allow more analysis before visualisation, but: both languages also have libraries to encapsulate interaction via SPARQL (rdflib/sparqlwrapper and SPARQL/RCurl respectively) one should decide whether more analysis should first be carried out using SPARQL
  • Exercise If you havent so far, click on one of the (HotW) 100 Objects (such as number 70, Hoa Hakananai'a Easter Island Statue) having run the main queryhaving run the main query Choose a material and observe the query for other objects in this material Adapt this query to count how many BM objects are made from basalt
  • Solution & Exercise Exercise: Now count the top ten materials and the number of objects for each
  • Solution
  • A Last Word SPARQLing a native RDF database (often called a triplestore) is not the only option before defaulting to programming A native graph database indexes the A native graph database indexes the graph in a different way, supporting traversal-oriented queries
  • Exercise Double click
  • Exercise Double click

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