1. Accessibility

1.1 Availability 1.2 Licensing 1.3 Interlinking 1.4 Security 1.5 Performance

2. Intrinsic

2.1 Semantic Accuracy 2.2 Consistency 2.3 Conciseness

3. Trust

3.1 Reputation 3.2 Believability 3.3 Verifiability

4. Dataset dynamicity

4.1 Currency 4.2 Timeliness

5. Contextual

5.1 Completeness 5.2 Amount of data

6. Representational

6.1 Representational-conciseness 6.2 Interoperability 6.3 Understandability 6.4 Interpretability 6.5 Versatility

7. Score

8. Vocabularies considered during the analysis

Accessibility
Metric Ref
Availability
Accessibility of the SPARQL endpoint bit.ly/4a4xRA6 Checking whether the server responds to a SPARQL query
Input Metadata
Algorithm Availability/SPARQL-endpoint
Output 0 The SPARQL endpoint is offline.
1 The SPARQL endpoint is online.
-1 The SPARQL endpoint is missing.
Accessibility of the RDF dump bit.ly/4a4xRA6 Checking whether an RDF dump is provided and can be downloaded
Input Metadata, (working) SPARQL endpoint, VoID file
Algorithm Availability/RDF-Dump
Output 0 The RDF dump is offline.
1 The RDF dump is online.
-1 The RDF dump is missing.
Derefereaceability of the URI bit.ly/3R8tYBA HTTP URIs should be dereferenceable, i.e. HTTP clients should be able to retrieve the resources identified by the URI
Input (working) SPARQL endpoint
Algorithm Availability/URIs-dereferenciability
Output [0,1] Best value: 1.
Licensing
Machine-redeable license bit.ly/4a4xRA6 detection of the indication of a license in the VoID description or in the dataset itself
Input Metadata, VoID file, (working) SPARQL endpoint
Algorithm Licensing/MR-License
Output 0 The license can't be recovered
1 The license can be recovered
Human-readable license bit.ly/4a4xRA6 Detection of a license in the documentation of the dataset
Input (working) SPARQL endpoint
Algorithm Licensing/Human-readable
Output 0 The license can't be recovered
1 The license can be recovered
Interlinking
Degree of connection bit.ly/4a4xRA6 detection of (a) interlinking degree, (b) clustering coefficient, (c) centrality, (d) open sameAs chains and (e) description richness through sameAs by using network measures
Input Metadata
Algorithm Interlinking/Degr-Connection
Output N Number of external links
Clustering coefficient https://bit.ly/4a4xRA6 (i) detection of (a) interlinking degree, (b) clustering coefficient, (c) centrality, (d) open sameAs chains and (e) description richness through sameAs by using network measures
Input Metadata
Algorithm Interlinking/Clustering-coefficient
Output [0,1] Best value: 1
Centrality bit.ly/4a4xRA6 (i) detection of (a) interlinking degree, (b) clustering coefficient, (c) centrality, (d) open sameAs chains and (e) description richness through sameAs by using network measures
Input Metadata
Algorithm Interlinking/Centrality
Output [0,1] Best value: 1
sameAs chains bit.ly/4a4xRA6 (i) detection of (a) interlinking degree, (b) clustering coefficient, (c) centrality, (d) open sameAs chains and (e) description richness through sameAs by using network measures
Input (working) SPARQL endpoint
Algorithm Interlinking/sameAs
Output [0,1] Best value: 1
skos:*Match bit.ly/skosPr skos:closeMatch | skos:exactMatch | skos:broadMatch | skos:narrowMatch | skos:relatedMatch
Input (working) SPARQL endpoint
Algorithm Interlinking/skos:*Match
Output [0,1] Best value: 1
Security
Access to data is secure bit.ly/4a4xRA6 use of login credentials (or use of SSL or SSH)
Input (working) SPARQL endpoint
Algorithm Security/Sec-acc
Output 0 Authentication is required
1 No authentication required
Access to data is secure bit.ly/4a4xRA6 HTTPS support
Input (working) SPARQL endpoint
Algorithm Security/https
Output 0 Does not use HTTPS
1 Use HTTPS
Performance
Low latency bit.ly/4a4xRA6 if an HTTP-request is not answered within an average time of one second, the latency of the data source is considered too low
Input (working) SPARQL endpoint
Algorithm Performance/Latency
Output [0,1] 1 if latency less than 1'' otherwise 1000/avg latency
High Throughput bit.ly/4a4xRA6 no. of answered HTTP-requests per second
Input (working) SPARQL endpoint
Algorithm Performance/Throughput
Output [0,1] 1 if more than 5 requests otherwise num of fulfilled requests/200
Intrinsic
Semantic Accuracy
Empty annotation labels bit.ly/41dNO2P labels, comments, notes which identifies triples whose property’s object value is empty string
Input (working) SPARQL endpoint
Algorithm Accuracy/Empty-label
Output [0,1] Best value: 1
White space in annotation bit.ly/41dNO2P presence of white space in labels
Input (working) SPARQL endpoint
Algorithm Accuracy/Whitespace
Output [0,1] Best value: 1
Datatype consistency bit.ly/41dNO2P Incompatible with data type range
Input (working) SPARQL endpoint
Algorithm Accuracy/Datatype
Output [0,1] Best value: 1
Functional property violation bit.ly/3Rts9QV FP = 1 - num of triples of with inconsistent values for functional properties / num of triples
Input (working) SPARQL endpoint
Algorithm Accuracy/FP
Output [0,1] Best value: 1
Inverse functional violation bit.ly/3Rts9QV IFP = 1 - num of triples of with inconsistent values for functional properties / num of triples
Input (working) SPARQL endpoint
Algorithm Accuracy/IFP
Output [0,1] Best value: 1
Consistency
Entities as members of disjoint classes bit.ly/4a4xRA6 no. of entities described as members of disjoint classes / total no. of entities described in the dataset
Input (working) SPARQL endpoint
Algorithm Consistency/Disjoint
Output [0,1] Best value: 1
Misplaced classes or properties bit.ly/4a4xRA6 Detection of a URI defined as a class is used as a property or a URI defined as a property is used as a class
Input (working) SPARQL endpoint
Algorithm Consistency/Misplaced
Output [0,1] Best value: 1
Use of members of deprecated classes or properties bit.ly/4a4xRA6 detection of use of OWL classes owl:DeprecatedClass and owl:DeprecatedProperty
Input (working) SPARQL endpoint
Algorithm Consistency/Deprecated
Output [0,1] Best value: 1
Invalid usage of undefined classes and properties bit.ly/4a4xRA6 detection of classes and properties used without any formal definition
Input (working) SPARQL endpoint
Algorithm Consistency/Undefined
Output [0,1] Best value: 1
Ontology hijacking bit.ly/4a4xRA6 detection of the redefinition by third parties of external classes/ properties such that reasoning over data using those external terms is affected
Input (working) SPARQL endpoint
Algorithm Consistency/Hijacking
Output [0,1] Best value: 1
Conciseness
Intensional conciseness bit.ly/4a4xRA6 number of unique attributes of a dataset in relation to the overall number of attributes in a target schema
Input (working) SPARQL endpoint
Algorithm Conciseness/Int-Conc
Output [0,1] Best value: 1
Extensional conciseness bit.ly/4a4xRA6 number of unique objects in relation to the overall number of object representations in the datase
Input (working) SPARQL endpoint
Algorithm Conciseness/Ext-Conc
Output [0,1] Best value: 1
Trust
Reputation
Reputation of the dataset bit.ly/41dNO2P analyzing page rank of the dataset
Input Metadata
Algorithm Reputation/PageRank
Output [0,1] Best value: 1
Believability
Meta-information about the identity of information provider bit.ly/41dNO2P checking whether the provider/contributor is contained in a list of trusted providers
Input Metadata
Algorithm Believability/Meta-info
Output [0,1] Best value: 1
Verifiability
Verifying publisher information bit.ly/41dNO2P stating the author and his contributors, the publisher of the data and its sources
Input (working) SPARQL endpoint, VoID file
Algorithm Verifiability/Publisher-info
Output 0 If no information are provided
1 1 if all information are provided
Verifying authenticity of the dataset bit.ly/41dNO2P whether the dataset uses a provenance vocabulary
Input (working) SPARQL endpoint, VoID file
Algorithm Verifiability/Vocabs
Output [0,1] Best value: 1
Verifying usage of digital signatures bit.ly/41dNO2P signing a document containing an RDF serialisation or signing an RDF graph
Input (working) SPARQL endpoint
Algorithm Verifiability/Publisher-info
Output 0 0 if the signature is not present
1 0 if the signature is present
Dataset dynamicity
Currency
Time since the last modification bit.ly/3RtIeWV currency only measures the time since the last modification
Input (working) SPARQL endpoint, VoID file
Algorithm Currency/LastModification
Output 0 if the modification date is correctly retrieved
1 otherwise
Specification of the modification date of statements bit.ly/3RtIeWV use of dates as the point in time of the last verification of a statement represented by dcterms:modifieds
Input (working) SPARQL endpoint, VoID file
Algorithm Currency/Modification
Output 0 if the modification date can't be retrieved
1 if the modification date is correctly retrieved
Age of data bit.ly/3RtIeWV current time - created time
Input (working) SPARQL endpoint, VoID file
Algorithm Currency/AgeOfData
Output 0 if the creation date can't be recovered
1 if the creation date is correctly recovered
Timeliness
Stating the recency and frequency of data validation bit.ly/3RtIeWV it corresponds to the "stating the [...] frequency of data validation"
Input (working) SPARQL endpoint
Algorithm Timeliness/Frequency
Output 0 if the frequency can't be retrieved
1 if the frequency is correctly retrieved
Contextual
Completeness
Interlinking completeness bit.ly/3RtIeWV degree to which interlinks are not missing
Input Metadata
Algorithm Completeness/Interl
Output [0,1] Best value: 1
Amount of data
Number of triples bit.ly/3RtIeWV Number of triples
Input Metadata, (working) SPARQL endpoint
Algorithm AmountOfData/Triples
Output 0 if the number of triples can't be retrieved
1 if the number of triples can be retrieved
Level of detail bit.ly/3RtIeWV Number of properties
Input VoID file, (working) SPARQL endpoint
Algorithm AmountOfData/Property
Output 0 if the number of property can't be retrieved
1 if the number of property can be retrieved
Scope bit.ly/3RtIeWV Number of entities
Input VoID file, (working) SPARQL endpoint
Algorithm AmountOfData/Entities
Output 0 if the number of entity can't be retrieved
1 if the number of entity can be retrieved
Representational
Representational-conciseness
Keeping URI short bit.ly/3RtIeWV detection of long URIs or those that contain query param-eters
Input (working) SPARQL endpoint
Algorithm Rep-Conc/ShortUri
Output [0,1] Best value: 1
Interoperability
Re-use of existing vocabularies bit.ly/3RtIeWV usage of established vocabularies
Input (working) SPARQL endpoint
Algorithm Rep-Cons/NewVocabs
Output 0 if there are new vocabularies
1 if all used vocabularies are already defined
Re-use of existing terms bit.ly/3RtIeWV detection of whether existing terms from all relevant vo-cabularies for that particular domain have been reuse
Input (working) SPARQL endpoint
Algorithm Rep-Cons/NewTerms
Output 0 if there are new terms
1 if all used terms are already defined
Understandability
Human-readable labelling of classes, properties and entities by providing rdfs:label bit.ly/3RtIeWV no. of entities described by stating an rdfs:label or rdfs:comment in the dataset / total no. of entities described in the data
Input (working) SPARQL endpoint
Algorithm Under/Label
Output [0,1] Best value: 1
Indication of metadata about a dataset bit.ly/3RtIeWV checking for the presence of the title, content and URI of the dataset
Input Metadata
Algorithm Under/info
Output 0 if there aren't all information
1 if there are all information required
Indication of an exemplary SPARQL query bit.ly/3RtIeWV detecting whether examples of SPARQL queries are provided
Input Metadata
Algorithm Under/example
Output 0 if there is no example
1 if at least one example is present
Indication of a regular expression that matches the URIs of a dataset bit.ly/3RtIeWV detecting whether a regular expression that matches the URIs is present
Input VoID file, (working) SPARQL endpoint
Algorithm Under/regex
Output 0 if the regex is not indicated
1 if the regex is indicated
Indication of the vocabularies used in the dataset bit.ly/3RtIeWV checking whether a list of vocabularies used in the dataset is provided
Input (working) SPARQL endpoint
Algorithm Under/Vocabs
Output [0,1] Best value: 1
Interpretability
No misinterpretation of missing values bit.ly/3RtIeWV detecting the use of blank nodes
Input (working) SPARQL endpoint
Algorithm Under/Bns
Output [0,1] Best value: 1
Atypical use of collections containers and reification bit.ly/3RtIeWV detection of the non-standard usage of collections, containers and reification
Input (working) SPARQL endpoint
Algorithm Under/Rdf
Output 0 if RDF structures are used.
1 if RDF structures aren't used.
Versatility
Usage of multiple languages bit.ly/3RtIeWV checking whether data is available in different languages
Input (working) SPARQL endpoint
Algorithm Versatility/Languages
Output 0 if no lang tag is retrieved
1 if at least a lang tag is retrieved
Different serialization formats bit.ly/3RtIeWV checking whether data is available in different serialization formats
Input (working) SPARQL endpoint
Algorithm Versatility/Serialization
Output 0 if no serialization format is provided
1 if at least a serialization format is provided
Accessing of data in different ways bit.ly/3RtIeWV cchecking whether the data is available as a SPARQL endpoint and is available for download as an RDF dump
Input (working) SPARQL endpoint
Algorithm Versatility/Access
Output 0 if the sparql endpoint or rdf dump is not online
1 if SPARQL endpoint and RDF dump are online.