Sasaki datathon-madrid-2015

1. Sasaki – LLD Datathon – Cercedilla, Spain, May 2015 Roundtripping of NIF based Linguistic Linked Data with non linked data sources Felix Sasaki DFKI / W3C Fellow Slides: http://de.slideshare.net/atcfsenzoku/sasaki-datathonmadrid2015 1

2. Sasaki – LLD Datathon – Cercedilla, Spain, May 2015 What is NIF? • Natural Language Processing Interchange Format – See http://nlp2rdf.org/ • LLD format to store annotations & to organize NLP pipelines • API specification to create NIF workflows • More details: after the coffee break  • Following slides: main roles for NIF 2

3. Sasaki – LLD Datathon – Cercedilla, Spain, May 2015 Example (Partial; JSON-LD Syntax) { "@graph" : [ { "@id" : "p:char=0,18", "@type" : [ "nif:Context", "nif:Sentence", "nif:RFC5147String" ], "anchorOf" : "Welcome to Prague.", "beginIndex" : "0", "endIndex" : "18", "isString" : "Welcome to Prague.", "referenceContext" : "p:char=0,18” }, { "@id" : "p:char=11,17", "@type" : [ "nif:RFC5147String", "nif:Word" ], … "referenceContext" : "p:char=0,18", "taIdentRef" : "http://dbpedia.org/resource/Prague" }, …] } 3

4. Sasaki – LLD Datathon – Cercedilla, Spain, May 2015 Example (Partial; JSON-LD Syntax) { "@graph" : [ { "@id" : "p:char=0,18", "@type" : [ "nif:Context", "nif:Sentence", "nif:RFC5147String" ], "anchorOf" : "Welcome to Prague.", "beginIndex" : "0", "endIndex" : "18", "isString" : "Welcome to Prague.", "referenceContext" : "p:char=0,18” }, { "@id" : "p:char=11,17", "@type" : [ "nif:RFC5147String", "nif:Word" ], … "referenceContext" : "p:char=0,18", "taIdentRef" : "http://dbpedia.org/resource/Prague" }, …] } 4 • Identifying and typing annotations • Identifying annotation offsets • Adding additional knowledge, e.g. named entity identifier • Interrelating annotations

8. Sasaki – LLD Datathon – Cercedilla, Spain, May 2015 A NIF workflow 8 Existing content Content analytics, e.g. named entity recognition Conversion to NIF Deploying knowledge from the LLD cloud

9. Sasaki – LLD Datathon – Cercedilla, Spain, May 2015 Potential scenario: roundtripping 9 Existing content Content analytics, e.g. named entity recognition Conversion to NIF Storing annotations in original content Deploying knowledge from the LLD cloud

10. Sasaki – LLD Datathon – Cercedilla, Spain, May 2015 Roundtripping • Roundtripping: Storing the outcome of content processing (analytics) tasks in the original content • Not always needed, but sometimes – examples: – Enriching Web content with named entity information; generating Schema.org markup via NIF pipelines. Format: HTML – Enriching localisation content, to add value beyond translation: Format: XLIFF 10

11. Sasaki – LLD Datathon – Cercedilla, Spain, May 2015 Example: HTML Example roundtripping workflow 11 … Welcome to Prague!… …Welcome to Prague!… 1) Conversion to NIF 2) NER processing 3) Back conversion to HTML

12. Sasaki – LLD Datathon – Cercedilla, Spain, May 2015 Example: XLIFF Example roundtripping workflow 12 … <xlf:source>Welcome to Prague!</xlf:source> … … <xlf:source>Welcome to <mrk … its:taClassRef="http://schema.org/Place">Prague </mrk>!</xlf:source> … 1) Conversion to NIF 2) NER processing 3) Back conversion to HTML

13. Sasaki – LLD Datathon – Cercedilla, Spain, May 2015 Example usage scenario: FREME project • See http://www.freme-project.eu/ • Developing interfaces for multilingual and semantic enrichment of digital content • Relies on NIF based enrichment workflows – See FREME API version 0.1 http://api.freme-project.eu/doc/0.1/ • Deploys aspects of the LIDER reference architecture for LLD processing – See D3.1.1 at http://lider-project.eu/?q=doc/deliverables • Focuses on four business cases – Localization BC requires XLIFF roundtripping – Web content personalisation BC requires HTML roundtripping 13

14. Sasaki – LLD Datathon – Cercedilla, Spain, May 2015 Challenges for roundtripping • Source format – How to store enrichment information (annotations) – How to handle existing information • Annotation model – NIF = a general graph-based annotation model – Sources format and annotation motivation may require restriction of the model 14

15. Sasaki – LLD Datathon – Cercedilla, Spain, May 2015 How to store annotations in various source formats • Solvable for markup languages like HTML or XLIFF • Challenge to preserve existing markup “Welcome to Prague!” • General issue with complex and proprietary formats: – “My own” storage mechanism = no tool support – Using existing storage mechanisms may mean: overloading semantics 15

16. Sasaki – LLD Datathon – Cercedilla, Spain, May 2015 Source format example: Word … <w:t>Welcome to Prague!</w:t> … 16 … <w:commentRangeStart w:id="0"/><w:t>Prague</w:t> <w:commentRangeEnd w:id="0"/> <w:r w:rsidR="00987079"> … <w:p w:rsidRPr="00987079">… Enrichment: type "http://schema.org/Place"…</w:p> Enrichment process; storing enrichment as comments Change of original content: creation of anchor Comment stored separately; refers to anchor: “standoff approach” Content storage Comment storage Content storage (Word file unzipped)

17. Sasaki – LLD Datathon – Cercedilla, Spain, May 2015 Annotation models • NIF: like RDF = general graph model – Consisting of nodes and arcs 17 p:char=11,17 dbp:Prague taIdentRef

18. Sasaki – LLD Datathon – Cercedilla, Spain, May 2015 Restricting graphs: Tree structured annotations on several layers 18 • Tree structures for syntactic annotations • Several annotation layers for the same text • Concurrent hierarchies • Representation only of one of these in roundtripping with XML Example taken from TEI http://www.tei-c.org/release/doc/tei-p5-doc/en/html/NH.html

19. Sasaki – LLD Datathon – Cercedilla, Spain, May 2015 Representing overlapping hierarchies with markup (1/2) Solutions advertised by the TEI • Multiple encoding of the same information – One XML document per annotation • Boundary marking with empty “milestone” elements – Also used by XLIFF 19

20. Sasaki – LLD Datathon – Cercedilla, Spain, May 2015 Representing overlapping hierarchies with markup (2/2) Solutions advertised by the TEI • Fragmentation and reconstitution of virtual elements – One hierarchy explicit, others with interrelated marked-up spans • Stand-off markup – Separation of text and annotations, interlinked via anchor and reference – Cf. Word example 20

21. Sasaki – LLD Datathon – Cercedilla, Spain, May 2015 Representing overlapping hierarchies in RDF POWLA (cf. Chiarcos, 2012) • RDF representation for corpus annotation, based on PAULA XML Standoff format • Allows to represent hierarchical, multi-layer corpora in RDF and query in SPARQL • Not relevant for roundtripping, but for linguistic annotation representation and processing in RDF 21

22. Sasaki – LLD Datathon – Cercedilla, Spain, May 2015 Lessons learned • Choose the overlap solution that fits your roundtripping modelling and processing needs • Consider off-the-shelf tooling – For 100% hierarchical data: XPath / CSS selectors, DOM, … • Consider libraries – For extraction only: Tika http://tika.apache.org/ – For roundtripping: Okapi http://okapi.opentag.com/ - in FREME currently being adapted for roundtripping in selected formats • Make sure the annotation survives in the original format – cf. Word example – Soon to be made easier by using Okapi 22

23. Sasaki – LLD Datathon – Cercedilla, Spain, May 2015 Roundtripping of NIF based Linguistic Linked Data with non linked data sources Felix Sasaki DFKI / W3C Fellow 23