Tutorial

On this and next few pages, we will introduce the basics implemenation usage and example of RELD knowledge Graph.

Framework

The diagram shows the basic RELD Framework. This diagram explains the basic schema of the RELD. The edges represent the relations between different classes, while the rectangles represent classes in our schema. The complete explanation of vocabularies and ontologies is available in other sections. For the TTL version of schema, click on the link

Mapping to RELD

The following diagram shows an overview of all the steps requires to convert a relation extraction dataset to RDF and integrate it into an RDF-based RELD knowledge graph. The input is a relation extraction dataset available in different formats such as XML, txt, or JSON. Then a python script using RDFLib and other python libraries converts the dataset to RDF form. Furthermore, we use sameAs and DBpedia spotlight to link entities with other large knowledge bases such as DBpedia and Wikidata . In addition, we use tools like Spacy and NLTK to add missing annotations. Finally combines all the previous steps using RELD schema and makes it available publicly using a dereferenceable knowledge graph using LodView.

Used Namespaces

Some of the namespaces we used in RELD:

@prefix reldr: <http://reld.dice-research.org/resource/>
@prefix reldp: <http://reld.dice-research.org/property/>
@prefix dbo: <http://dbpedia.org/ontology/>
@prefix dc: <http://purl.org/dc/elements/1.1/>
@prefix freebase: <http://rdf.freebase.com/ns>
@prefix owl: <http://www.w3.org/2002/07/owl#>
@prefix ps: <http://www.wikidata.org/prop/statement/>
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>
@prefix xml: <http://www.w3.org/XML/1998/namespace>
@prefix xsd: <http://www.w3.org/2001/XMLSchema#>
@prefix prov: <http://www.w3.org/ns/prov#>
@prefix schema: <http://schema.org/>
@prefix dicom: <http://purl.org/healthcarevocab/v1>
@prefix dcterms: <http://purl.org/dc/terms/>
@prefix nif: <http://persistence.uni-leipzig.org/nlp2rdf/ontologies/nif-core#>
@prefix foaf: <http://xmlns.com/foaf/0.1/>
@prefix void: <http://rdfs.org/ns/void#>
@prefix bibtex: <http://purl.org/net/nknouf/ns/bibtex#>
@prefix dcat: <http://www.w3.org/ns/dcat>
@prefix prof: <http://www.w3.org/ns/dx/prof/hasToken>

Example Resource

Following is an example resource:

@prefix nif: <http://persistence.uni-leipzig.org/nlp2rdf/ontologies/nif-core#>
@prefix ns1: <http://www.w3.org/ns/dx/prof/>
@prefix ns2: <http://purl.org/net/nknouf/ns/bibtex#>
@prefix ns3: <http://www.w3.org/ns/>
@prefix owl: <http://www.w3.org/2002/07/owl#>
@prefix prov: <http://www.w3.org/ns/prov#>
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>
@prefix reld: <http://reld.dice-research.org/schema/>
@prefix reldr: <http://reld.dice-research.org/resource/>
@prefix reldp: <http://reld.dice-research.org/property/>
@prefix xsd: <http://www.w3.org/2001/XMLSchema#>

# STRING INSTANCE
reldr:S-1375181 a nif:String ;
   ns2:hasTitle "Sonic Extreme"^^xsd:string ;
   reldr:hasPOS reldr:posSeq1375181 ;
   reldr:hasPunctuation reldr:puncSeq1375181 ;
   reld:hasNamedEntity reldr:sonic,
   reldr:sonic_extreme ;
   reld:hasStatement reldr:Stmt13751810 ;
   reld:numSent "2"^^xsd:int ;
   reld:strType "document"^^xsd:string ;
   ns3:dcatdistribution "train"^^xsd:string ;
   ns1:hasToken reldr:token_1375181 ;
   prov:hadPrimarySource reldr:ds_08 .

# PARTS OF SPEACH POS INSTANCE
reldr:posSeq1375181 a reld:POS ;
   rdf:_0 "JJ"^^xsd:string ;
   rdf:_1 "NNP"^^xsd:string ;
   rdf:_10 "NNP"^^xsd:string ;
   rdf:_11 "DT"^^xsd:string ;
   rdf:_12 "NNP"^^xsd:string ;
   rdf:_13 "NN"^^xsd:string ;
   rdf:_14 "IN"^^xsd:string ;
   rdf:_15 "DT"^^xsd:string ;
   rdf:_16 "NNP"^^xsd:string ;
   rdf:_17 "."^^xsd:string ;
   rdf:_18 "IN"^^xsd:string ;
   rdf:_19 "DT"^^xsd:string ;
   rdf:_2 "VBZ"^^xsd:string ;
   rdf:_20 "NN"^^xsd:string ;
   rdf:_21 "VBD"^^xsd:string ;
   rdf:_22 "RB"^^xsd:string ;
   rdf:_23 "RB"^^xsd:string ;
   rdf:_24 "VBN"^^xsd:string ;
   rdf:_25 ","^^xsd:string ;
   rdf:_26 "NN"^^xsd:string ;
   rdf:_27 "IN"^^xsd:string ;
   rdf:_28 "DT"^^xsd:string ;
   rdf:_29 "NN"^^xsd:string ;
   rdf:_3 "DT"^^xsd:string ;
   rdf:_30 "VBD"^^xsd:string ;
   rdf:_31 "VBN"^^xsd:string ;
   rdf:_32 "RB"^^xsd:string ;
   rdf:_33 "RB"^^xsd:string ;
   rdf:_34 "IN"^^xsd:string ;
   rdf:_35 "DT"^^xsd:string ;
   rdf:_36 "NN"^^xsd:string ;
   rdf:_37 "NN"^^xsd:string ;
   rdf:_38 "NN"^^xsd:string ;
   rdf:_39 "."^^xsd:string ;
   rdf:_4 "JJ"^^xsd:string ;
   rdf:_5 "NN"^^xsd:string ;
   rdf:_6 "NN"^^xsd:string ;
   rdf:_7 "NN"^^xsd:string ;
   rdf:_8 "IN"^^xsd:string ;
   rdf:_9 "DT"^^xsd:string .

# TOKEN INSTANCE
reldr:token_1375181 a reld:Token ;
   rdf:_0 "Sonic"^^xsd:token ;
   rdf:_1 "Extreme"^^xsd:token ;
   rdf:_10 "Sonic"^^xsd:token ;
   rdf:_11 "the"^^xsd:token ;
   rdf:_12 "Hedgehog"^^xsd:token ;
   rdf:_13 "series"^^xsd:token ;
   rdf:_14 "for"^^xsd:token ;
   rdf:_15 "the"^^xsd:token ;
   rdf:_16 "Xbox"^^xsd:token ;
   rdf:_17 "."^^xsd:token ;
   rdf:_18 "While"^^xsd:token ;
   rdf:_19 "the"^^xsd:token ;
   rdf:_2 "is"^^xsd:token ;
   rdf:_20 "game"^^xsd:token ;
   rdf:_21 "was"^^xsd:token ;
   rdf:_22 "never"^^xsd:token ;
   rdf:_23 "officially"^^xsd:token ;
   rdf:_24 "released"^^xsd:token ;
   rdf:_25 ","^^xsd:token ;
   rdf:_26 "footage"^^xsd:token ;
   rdf:_27 "of"^^xsd:token ;
   rdf:_28 "the"^^xsd:token ;
   rdf:_29 "game"^^xsd:token ;
   rdf:_3 "a"^^xsd:token ;
   rdf:_30 "was"^^xsd:token ;
   rdf:_31 "received"^^xsd:token ;
   rdf:_32 "very"^^xsd:token ;
   rdf:_33 "poorly"^^xsd:token ;
   rdf:_34 "by"^^xsd:token ;
   rdf:_35 "the"^^xsd:token ;
   rdf:_36 "video"^^xsd:token ;
   rdf:_37 "game"^^xsd:token ;
   rdf:_38 "press"^^xsd:token ;
   rdf:_39 "."^^xsd:token ;
   rdf:_4 "cancelled"^^xsd:token ;
   rdf:_5 "skateboarding"^^xsd:token ;
   rdf:_6 "video"^^xsd:token ;
   rdf:_7 "game"^^xsd:token ;
   rdf:_8 "in"^^xsd:token ;
   rdf:_9 "the"^^xsd:token .

# PUNCTUATION INSTANCE
reldr:puncSeq1375181 a reld:Punctuation ;
   rdf:_0 "."^^xsd:string ;
   rdf:_1 ","^^xsd:string
   rdf:_2 "."^^xsd:string .

# STATEMENT INSTANCE
reldr:Stmt13751810 a rdf:Statement ;
   reld:objEndIndex 7 ;
   reld:objStartIndex 6 ;
   reld:subEndIndex 1 ;
   reld:subFollowObj false ;
   reld:subStartIndex 0 ;
   rdf:object reldr:video_game ;
   rdf:predicate reldp:P31 ;
   rdf:subject reldr:sonic_extreme .

# SUBJECT/ENTITY INSTANCE
reldr:sonic_extreme a rdfs:Resource,
   prov:Entity ;
   rdfs:label "Sonic_Extreme"^^xsd:string,
   "sonic_extreme"^^xsd:string .

# OBJECT INSTANCE
reldr:brave_video_game a rdfs:Resource ;
   rdfs:label "Brave_video_game"^^xsd:string .

# PREDICATE INSTANCE
reldp:P31 a rdf:Property ;
   rdfs:label "P31"^^xsd:string ;
   owl:equivalentProperty reldp:instance_of .

# DATASET INSTANCE
reldr:ds_08 a reld:Dataset ;
   dbo:knownFor "relation_extraction_and_natural_language"^^xsd:string ;
   dc:title "T-REx"^^xsd:string ;
   dcterms:language "en"^^xsd:string ;
   dicom:datasetType "document"^^xsd:string ;
   schema:url <https://hadyelsahar.github.io/t-rex/downloads> .

Some useful queires

# Get all Relations from NYT-FB dataset.

SELECT DISTINCT ?relation
FROM <http://reld.dice-research.org/Nyt-FB>
WHERE {
   ?s a rdf:Statement;
      rdf:predicate ?relation.
}

#Get all triples from Wikipedia-Wikidata

SELECT DISTINCT count(*)
FROM <http://reld.dice-research.org/WikiRE>
WHERE {
   ?s ?p ?o .
}

# Get all distinct String instances which have number of tokens higher than 250

PREFIX reld: <http://reld.dice-research.org/schema/>
PREFIX nif: <http://persistence.uni-leipzig.org/nlp2rdf/ontologies/nif-core#>
PREFIX prof: <http://www.w3.org/ns/dx/prof/>
SELECT DISTINCT ?sent
WHERE {
   ?sent a nif:String;
         prof:hasToken ?token.

   ?token ?p ?o.
}
GROUP BY ?sent
HAVING (COUNT (?token ) > 250)

# Select all sentences containing more than 50 named entities

PREFIX reld: <http://reld.dice-research.org/schema/>
PREFIX nif: <http://persistence.uni-leipzig.org/nlp2rdf/ontologies/nif-core#>
PREFIX prof: <http://www.w3.org/ns/dx/prof/>
PREFIX prov: <http://www.w3.org/ns/prov#>
SELECT DISTINCT ?sent
WHERE {
?sent a nif:String;
   reld:hasNamedEntity ?ent.
}
GROUP BY ?sent
HAVING (COUNT (?ent) > 50)

# Select all distinct relations with averges of subject and object start indices

PREFIX reldv: <http://reld.dice-research.org/schema/>
PREFIX nif: <http://persistence.uni-leipzig.org/nlp2rdf/ontologies/nif-core#>
PREFIX prof: <http://www.w3.org/ns/dx/prof/>
PREFIX prov: <http://www.w3.org/ns/prov#>

SELECT DISTINCT ?r (AVG(?subIndex) as ?avgSubStrtIdx) (AVG(?objIndex) as ?avgObjStrtIdx)
WHERE {
   ?stmt a rdf:Statement;
   rdf:predicate ?r;
   reldv:subStartIndex ?subIndex;
   reldv:objStartIndex ?objIndex.

}

# Generate benchmark of having sentences length less than 50, and other required features

PREFIX reld:<http://reld.dice-research.org/schema/>
PREFIX nif:<http://persistence.uni-leipzig.org/nlp2rdf/ontologies/nif-core#>
PREFIX prof:<http://www.w3.org/ns/dx/prof/>
SELECT DISTINCT
?sent ( count(?t ) as ?Tokens) ( count (?e) as ?Entities) ( count(?stmt) as ?Statment)
WHERE
{
   ?sent a nif:String ;
   reld:hasStatement ?stmt ;
   reld:hasNamedEntity ?e ;
   prof:hasToken ?token .
   ?token ?p ?t .
}
GROUP BY ?sent
HAVING ( COUNT(?stmt) > 4 && COUNT (?e) > 10 && COUNT(?t ) < 50)

# A balance dataset of relations each having 700 sentneces

PREFIX reld:<http://reld.dice-research.org/schema/>
PREFIX nif:<http://persistence.uni-leipzig.org/nlp2rdf/ontologies/nif-core#>
PREFIX prof:<http://www.w3.org/ns/dx/prof/>
SELECT DISTINCT ?properties COUNT(?sent )
WHERE {
   ?sent a nif:String ;
   reld:hasStatement ?stmt .
   ?stmt rdf:predicate ?properties .
}
GROUP BY ?properties
HAVING ( COUNT(?sent ) = 700)

Dereferencing

We also allow dereferencing our dataset URIs using the LodView link. LodView allows RELD users to browse our RDF resource and offers an easy-to-use representation of the RDF data. An example resource from LodView is shown in the following figure. To see it online, click here

Usage

Named Graphs

To use the data of a single relation extraction dataset RELD uses a named graph. Named graphs in RELD are kept using the http://reld.dice-research.org/dataset_name. dataset_name in URI represents the name of each dataset. For simplicity, we use the names of the datasets as shown in the following Table . Few datasets names are shorten for simplicity.

Named Graphs with their used URIs in RELD

Dataset	Named Graphs
SemEval 2010 Task 8	http://reld.dice-research.org/SemEval
NYT-FB	http://reld.dice-research.org/Nyt-FB
FewREL	http://reld.dice-research.org/FewRel
Google-RE	http://reld.dice-research.org/Google-RE
WebNLG	http://reld.dice-research.org/WebNLG
Wikipedia-Wikidata	http://reld.dice-research.org/WikiRE
DocRED	http://reld.dice-research.org/DocRed
T-REx	http://reld.dice-research.org/T-Rex

nif:String

Sentences/Documents are represented in the String IRI format as http://reld.dice-research.org/resource`S_ID`. ID in S_ID is the unique value for each string or document. All the properties of the sentences/documents are attached to the sentences. The detail of each property is available in our schema.

rdf:Statement

Each string has a corresponding single or multiple annotated statements. This RDF statement also has a unique IRI like the nif:String. Each statement has an attached Subject and the object also has an attached predicate which represents the corresponding relation.

Relation

Relations are attached with statements as rdf:predicate. The IRI is different than other resources to uniquely differentiate predicate from other resources. Instead of resource we use property for relations http://reld.dice-research.org/property/property_name.

RELD Prefered Namespaces

We use three different namespaces for RELD.

• reld: for schema of reld such as classes and properties

• reldr: for resources such as instances

• reldp: for properties/predicates

Namespaces with IRIs

Namespaces	IRI
reld	http://reld.dice-research.org/schema/
rledr	http://reld.dice-research.org/resource/
reldp	http://reld.dice-research.org/property/

RELD Metadata in Void

We represents metadata of RELD in void representation.

@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
@prefix dcterms: <http://purl.org/dc/terms/> .
@prefix void: <http://rdfs.org/ns/void#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix reldr: <https://reld.dice-research.org/resource/> .
@prefix : <#> .

:RELD
   rdf:type void:Dataset ;
   foaf:homepage <https://reld-tutorial.readthedocs.io/en/latest/intro.html> ;
   dcterms:title "Knowledge Graph of Relation Extraction" ;
   void:sparqlEndpoint <http://reld.cs.upb.de:8890/sparql>;
   dcterms:contributor <https://dice-research.org> ;
   dcterms:source <https://github.com/dice-group/RELD> ;
   dcterms:modified "2022-11-03"^^xsd:date ;
   dcterms:publisher :Manzoor_Ali ;
   dcterms:publisher :Muhammad_Saleem ;
   dcterms:publisher :Diego_Moussallem ;
   dcterms:publisher :Mohamed_Ahmed_Sherif ;
   dcterms:publisher :Axel-Cyrille_Ngonga_Ngomo ;
   dcterms:license <https://creativecommons.org/licenses/by-nc/3.0/> ;
   void:feature <https://www.w3.org/ns/formats/data/Turtle> ;
   void:fearure <https://www.w3.org/ns/formats/data/JSON-LD>;
   void:triples 55305748 ;
   void:vocabulary <http://reld.dice-research.org/resource/> ;
   void:vocabulary <http://reld.dice-research.org/schema/> ;
   void:vocabulary <http://purl.org/ontology/bibo/> ;
   void:vocabulary <http://purl.org/net/nknouf/ns/bibtex#> ;
   void:vocabulary <http://purl.org/dc/terms/> ;
   void:vocabulary <http://xmlns.com/foaf/0.1/> ;
   void:vocabulary <http://www.w3.org/2005/11/its/rdf#> ;
   void:vocabulary <http://www.w3.org/ns/prov#> ;
   void:vocabulary <http://www.w3.org/1999/02/22-rdf-syntax-ns#> ;
   void:vocabulary <http://www.w3.org/2000/01/rdf-schema#> ;
   void:vocabulary <http://schema.org/> ;
   void:vocabulary <http://www.w3.org/2006/vcard/ns#> ;
   void:vocabulary <http://www.w3.org/XML/1998/namespace> ;
   void:vocabulary <http://www.w3.org/2001/XMLSchema#> ;
   void:vocabulary <https://data.linkeddatafragments.org/> ;
   void:linkPredicate rdfs:seeAlso ;
   void:linkPredicate rdfs:label ;
   void:linkPredicate rdf:type ;
   void:linkPredicate owl:equivalenProperty ;
   void:linkPredicate owl:sameAs .

reldr:Google_RE a void:Dataset;
   void:target <https://reld.dice-research.org/>;
   void:target <https://github.com/google-research-datasets/>;
   void:linkPredicate owl:sameAs;
   void:triples 685633 .

reldr:NYT-FB a void:Dataset;
   void:target <https://reld.dice-research.org/>;
   void:target <http://iesl.cs.umass.edu/riedel/ecml/>;
   void:linkPredicate owl:sameAs;
   void:triples 3119910 .
reldr:FewRel a void:Dataset;
   void:target <https://reld.dice-research.org/>;
   void:target <https://www.zhuhao.me/fewrel/>;
   void:linkPredicate owl:sameAs;
   void:triples 1288803 .
reldr:SemEval a void:Dataset;
   void:target <https://reld.dice-research.org/>;
   void:target <http://www.kozareva.com/>;
   void:linkPredicate owl:sameAs;
   void:triples 188991 .

reldr:WebNLG a void:Dataset;
   void:target <https://reld.dice-research.org/>;
   void:target <https://webnlg-challenge.loria.fr/>;
   void:linkPredicate owl:sameAs;
   void:triples 1863267 .

reldr:Wiki-RE a void:Dataset;
   void:target <https://reld.dice-research.org/>;
   void:target <https://www.informatik.tu-darmstadt.de/ukp/research_ukp/ukp_research_data_and_software/>;
   void:linkPredicate owl:sameAs;
   void:triples 41156660 .

reldr:docRed a void:Dataset;
   void:target <https://reld.dice-research.org/>;
   void:target <https://github.com/thunlp/DocRED>;
   void:linkPredicate owl:sameAs;
   void:triples 2487493 .
reldr:t-rex a void:Dataset;
   void:target <https://reld.dice-research.org/>;
   void:target <https://hadyelsahar.github.io/t-rex/downloads/>;
   void:linkPredicate owl:sameAs.

:Manzoor_Ali a
   foaf:Person ;
   rdfs:label "Manzoor Ali" ;
   foaf:homepage <https://dice-research.org/ManzoorAli>;
   foaf:mbox <mailto:manzoor@mail.uni-paderborn.de> .


:Muhammad_Saleem a
   foaf:Person ;
   rdfs:label "Muhammad Saleem" ;
   foaf:homepage <https://dice-research.org/MuhammadSaleem>;
   foaf:mbox <mailto:saleem@informatik.uni-leipzig.de> .

:Diego_Moussallem a
   foaf:Person ;
   rdfs:label "Diego Moussallem" ;
   foaf:homepage <https://dice-research.org/DiegoMoussallem>;
   foaf:mbox <mailto:diego.moussallem@uni-paderborn.de> .

:Mohamed_Ahmed_Sherif a
   foaf:Person ;
   rdfs:label "Mohamed Ahmed Sherif" ;
   foaf:homepage <https://dice-research.org/MohamedAhmedSherif>;
   foaf:mbox <mailto:mohamed.sherif@upb.de> .


:Axel-Cyrille_Ngonga_Ngomo a
   foaf:Person ;
   rdfs:label "Axel-Cyrille Ngonga Ngomo" ;
   foaf:homepage <https://dice-research.org/AxelCyrilleNgongaNgomo>;
   foaf:mbox <mailto:axel.ngonga@upb.de> .