VocBench. A Web Application for Collaborative Development of Multilingual Thesauri

Transcription

1 University of Rome Tor Vergata VocBench A Web Application for Collaborative Development of Multilingual Thesauri Armando Stellato +, Sachit Rajbhandari*, Andrea Turbati +, Manuel Fiorelli + Caterina Caracciolo*, Tiziano Lorenzetti +, Johannes Keizer*, Maria Teresa Pazienza + + ART Group, Dept of Enterprise Engineering, University of Rome Tor Vergata, Via del Politecnico 1, Rome, Italy *Food and Agricultural Organization of the United Nations (FAO), Viale delle Terme di Caracalla, Rome, Italy Contacts: {surname}@info.uniroma2.it {name.surname}@fao.org Portoroz, Slovenia, 31 st May - 4 th June 2015

2 Why was it built? AGROVOC (big agriculture vocabulary developed by FAO) > concepts in up to 22 languages A global group of terminologists. No tool to support their work No existing tool that met all of FAO s needs 03/06/ th ESWC, Portoroz, Slovenia 2

3 V Google Web Toolkit (for the Web Application) Lucene (for label indexing & free-text search) Protégé API DB backend (later) OWLART API MySQL Custom model for thesaurus representation GWT / Presentation Business logic Protégé 3.4 MySQL OWLART API 03/06/ th ESWC, Portoroz, Slovenia 3

4 V /06/ th ESWC, Portoroz, Slovenia 4

5 V1.x Problems Could not support other triple stores (Glued to Protégé API) Custom representation model No support for emerging standards, e.g. SKOS I/O No import Complicated export No support for alignments AGROVOC aligned to a dozen other vocabularies No SPARQL interface 03/06/ th ESWC, Portoroz, Slovenia 5

6 Towards VB2.0 Many of VB1.x limitations derived from the absence of a true RDF Backend not just connection to a RDF triple store but a proper abstraction layer providing high level functionalities for ontology/thesaurus management Driving lines for VB2.0 A completely rebuilt backing framework for the service and data layers, based on an already existing open source project: Semantic Turkey [1] Based on OSGi Open Services Gateway Open Connectibility to most notable RDF middleware and triple storing technologies (Sesame2, OWLIM, Allegrograph, Jena (not maintained) ) Native support for SKOS and SKOSXL over RDF (no more conversions from internal legacy models), other than OWL major reworking all changes under-the-hood, and leaving user experience almost unchanged. New features added in the following versions [1] Maria Teresa Pazienza, Noemi Scarpato, Armando Stellato and Andrea Turbati Semantic Turkey: A Browser-Integrated Environment for Knowledge Acquisition and Management, Semantic Web Journal, vol. 3, no. 3, /06/ th ESWC, Portoroz, Slovenia 6

7 Objectives and Requisites for a V2 R1. Multilingualism R2. Controlled Collaboration R3. Data Interoperability and Consistency R4. Software Interoperability/Extensibility R5. Scalability R6. Under-the-hood data access/modification R7. Ease-of-use for both users and system administrators 03/06/ th ESWC, Portoroz, Slovenia 7

8 and here we are

9 R1. Multilingualism and multilingual UI: (currently: English, Spanish, Dutch, Thai) multilingual editing and visualization

10 R2. Controlled Collaboration (1/3) Role-based Access Control 03/06/ th ESWC, Portoroz, Slovenia 10

11 R2. Controlled Collaboration (2/3) Formal Editorial Workflow Following the full life-cycle of concepts/terms, from proposal to deprecation Supported by Role-based Access Control GUEST <concept-create> Proposed by guest VALIDATOR <validates> Validated PUBLISHER <publishes> Published an example of a typical workflow: ONTOLOGY EDITOR <concept-delete> Proposed deprecated ADMINISTRATOR <validates> Published TERM EDITOR <concept-edit> Revised PUBLISHER <validates> Deprecated 03/06/ th ESWC, Portoroz, Slovenia 11

12 R2. Controlled Collaboration (3/3) Recent Changes Available through a dedicated module or as RSS feeds includes both: User changes Content changes 03/06/ th ESWC, Portoroz, Slovenia 12

13 R3. Data Interoperability and Consistency (1/3) Formats Import/Export in all popular RDF serialization formats Concrete availability of the various formats depend however on the connected triple store/rdf middleware Models VocBench adopts a SKOS-XL + reified skos:definitions model Import of SKOS core data Export Refactoring for SKOS SKOS-XL and skos:definition reification SKOS-XL: All contents or Filtered export based on broader concept/schems SKOS: options for removing/keeping reified labels and definitions Vocabularies Possibility to owl:import any existing vocabulary, from the web or from local files. Availaibility of a caching mirror for previously imported vocabularies

14 R3. Data Interoperability and Consistency (2/3) Integrity / Consistency VB features a complex multi-scheme management of thesauri Actions creating potential breaks in the structure (e.g. breaking reachability of a concept) are forbidden To deal with imported data, Integrity Constraint Validation checks have been included in the platform Currently, only dangling concepts have been deal with More to come, already available as services from ST

15 R3. Data Interoperability and Consistency (2/3) Alignment 03/06/ th ESWC, Portoroz, Slovenia 15

16 R4. Software Interoperability/Extensibility Triple Store Agnostic GWT/Presentation OWLART API provide: a very tiny layer over existing middlewares (e.g. Sesame, Jena) High-level vocabulary layer for OWL, SKOS, SKOS-XL What triple stores do we currently support and which connectors are actively maintained? Sesame2 (standard internal triple stores, both in-memory and native) Business logic Semantic Turkey OWLART API GraphDB/OWLIM (through Sesame remote connection, and an optional parameter expressly dedicated to cover the different management of graphs wrt Sesame) Other partners have experimented with other triple stores Past experiments with Allegrograph and Jena Middleware For GraphDB/OWLIM SE, we exploit its free-text indexing capabilities High-level data access Raw triple access Vendor data access layer Vendor data access layer Vendor Triple store 03/06/ th ESWC, Portoroz, Slovenia 16

17 R5. Scalability Performance Information is provided to the frontend as much as possible in an incremental fashion (e.g., each level of the concept hierarchy, as nodes are expanded). Interfaces reverts to limited content and search-filtering for potentially exploding results Maintenance ST offers a meaningful core set of RDF services however many functionalities (especially in UI) require the composition of several calls. Solution: combo of: per-service ad-hoc solutions (heavy weight single services realizing specific functionalities) general development facilities for the injection of additional information into common API calls (e.g. the rendering of RDF resources is available as an extension point, with different implementations being dynamically injectable into the SPARQL queries of several services). 03/06/ th ESWC, Portoroz, Slovenia 17

18 R6. Under-the-hood data access/modification Embedded SPARQL Editor Syntax highlight completion and validation

19 R7. Ease-of-use for both users and system administrators Continuous check-on-start life cycle VB technically never recognizes itself as installed/deployed At each startup it checks that the complete set of pre-requisites for a correct start is satisfied. Whenever a new VB version is installed, if new features have been introduced, or mandatory configuration options added, or the database requires update batches, the system will identify these needs and react accordingly, eventually interacting with the user upon necessity 03/06/ th ESWC, Portoroz, Slovenia 19

20 Statistics Module 03/06/ th ESWC, Portoroz, Slovenia 20

21 Vocbench 2.0 (and ST) Architecture Three layered extensible architecture Presentation Layer GWT (Google Web Toolkit) Vocbench User Interface (Mozilla apps in the original framework) Services Layer Enables communication between the client (Vocbench UI) and the ontology persistence layer. HTTP based Services accessed through the Ajax paradigm OSGi Extensible Servicing System Persistence Layer Access to ontological knowledge. Based on dedicated ontology API, which can be implemented through use of different technologies. 03/06/

22 Vocbench 2.0 (and ST) Architecture Front end Middleware Back end Google Web Toolkit (GWT) Gilead Hibernate Layer Administrative Database (MySQL) GWT Incubator Graph Visualization Service Wrapper Layer Web services Semantic Turkey/ OWLART API Triple Store 03/06/ th ESWC, Portoroz, Slovenia 22

23 VB desktop version : Semantic Turkey for Firefox

24 Related Works (1/2) PoolParty: [18]. Web-based Editor for Thesauri using Linked Data Support for SKOS (optional add-on for SKOS-XL) Use: Commercial license (Evaluated thanks to a free evaluation account for PoolParty Advanced Server version (rev 5429) ) Version Tracking is supported, as the system performs access control to some extent. An add-on further enables an approval workflow based on the existing role based access control mechanism. Editing history is shown both at project level and at entity level. Alignment: lookup over LOD, or different projects can be linked together Publishes a SPARQL endpoint, dereferenceable URIs, and a wiki with limited editing capabilities. Quality criteria: can enforced interactively (i.e., illegal operations are blocked), or violations are simply recorded in a quality report. Backed by Sesame middleware Incorrect multiple scheme support (violates non -entailment of scheme containment along concept hierarchies, section of the SKOS Reference [1] ) TemaTres: Web-based Editor for Controlled Vocabularies term-based meta-model, no native support for SKOS Use: Free and open-source due to the term-based nature of the model, the export to SKOS is often confusing (e.g. two synonyms terms exported as two different concepts) Monolingual (though alignments between vocabularies) No multiple scheme support (each thesaurus is a scheme) Rigid access control mechanism based on user roles (administrator, editor, guest). Workflow management: term transition from candidate status to either accepted or rejected. Accepted cannot be reverted, even after modifications Data quality: metrics and a flexible reporting generator. Connectivity: available API and a few plugins (e.g. for publication over different platforms, such as WordPress) are available 03/06/ th ESWC, Portoroz, Slovenia 24

25 Related Works (2/2) TopBraid EVN: Web-based Editor for Business Vocabularies Support for SKOS, OWL Ontologies and Content tag sets Use: Commercial license (We didn t carry extensive evaluation as we did not receive the evaluation license we requested) SKOSEd: plugin for Protégé 4.x for editing SKOS thesauri Support for SKOS Use: free of use and open-source. We have evaluated version 1.0-alpha(build04) on Protégé 4.1 as, 2.0-alpha has a bug related to scheme management Desktop tool (no web application) Ontology editing, SKOSEd allows interweaving SKOS and OWL constructs (defect: same form for skos:concept and skos:conceptschemes Incorrect concept scheme management (same as PoolParty) Being an extension of Protégé 4.x, SKOSEd may not be used in conjunction with the collaboration framework developed for Protégé 3.x Web Protégé: [16] Collaborative Web-based Ontology Editor No support for SKOS/SKOS-XL (supports OWL/OBO editing) Use: local Installation or service via public portal. Free of use in both cases Collaboration: based on the collaboration plugin for Protégé 3 [17], providing: Change tracking Inline discussions and notifications. Access control mechanism for user groups, based on configurable policies enforced at various granularities. Completely configurable user interface Available API 03/06/ th ESWC, Portoroz, Slovenia 25

26 Functional Comparison Example 9 (non-entailment) <A> skos:narrower <B>. <A> skos:inscheme <MyScheme>. does not entail <B> skos:inscheme <MyScheme>. Name VocBench License GNU GPL v3 (web application), Mozilla Public License MPL (Semantic Turkey) Free to use Yes PoolParty Proprietary No WebProtégé TemaTres SKOSEd Mozilla Public License (MPL) GNU General Public License version 2.0 (GPLv2) GNU Lesser GPL Yes Yes Yes Deployme nt Web application Web application Web application Web application Desktop application Data Models SKOS-XL, SKOS through offline scaling tool SKOS, SKOS-XL add-on OWL 2, OBO Term based thesaurus organizatio n SKOS Import/ Export SKOS(- XL), versatile spreadshe et import (through ST Firefox UI) SKOS(- XL), static spreadshe et import OWL MADS, SKOS- Core, Zthes, Others Import from: Skos- Core, tabulated or tagged text file SKOS Scheme Managem ent Yes Only top concepts Not applicable One scheme per vocabulary Only top concepts Custom Relations Reasoner Data quality Creation, Import, use Creation, Import, use Creation, Import, use Creation, use Creation, Import, use Depends on triple store Depends on triple store No, external reasoning possible No Depends on available plugins Metrics Metrics Validation rules Metrics Metrics, Reports KB consistenc y Extendibility / Interoperability API, shared backend, pluggable REST API API, shared backend,plugg able API ACL Yes Yes Yes Yes; limited Workflow Managem ent Yes Yes (addon) No Yes; limited Collaborati on, Content Validation Change feed, validation History, versioning, validation Discussion, watching, changes feed Limited validation Pluggable No No No RDF Middlewar e OWL ART API (connector s to others: Sesame2 bundled) Sesame SAIL API OWL API No RDF Middlewar e, SKOS RDF/XML available only as an export OWL API (used by Protégé 4) RDF Backend provided by Sesame2, or other connectors provided by Sesame2 provided by Protégé 3 Relational database (MySQL by default) provided by Protégé 4 (OWL API) SPARQL Querying Yes Yes No Not native, no realtime, can export data to a SPARQL endpoint through ARC2 (RDF library for PHP) Yes (inherited from Protégé 4) Semantic Integration assisted (browse&search) linking of resources from other projects / manual linking of LOD resources. Extensions for RDF lifting from unstructured content Linking Text Mining & Entity Extraction, Search function linking to BioPortal Linking between vocabularies, Entity Extraction (via addon) N/A

27 User Community and Evaluation (1/2) Here is a list of relevant organizations * adopting, or close to adopting, VB2.0: Food and Agriculture Organization (FAO) > AGROVOC, Biotechnology, Land and Water, FAO Topics EU Documentation Office > EUROVOC Italian Senate > TESEO European Environment Agency (EEA) > GEMET Harvard University > Unified Astronomy Thesaurus (UAT) 2 VB community mailing lists: - VB user forum - VB developer forum EC Parliament Library Agence Nationale de la Recherche > Infrastructure nationale AnaEE France CABI United Nations Convention to Combat Desertification (UNCCD) Scottish Government > Gov metadata Columbia University > IEDA Thesaurus * 03/06/ th ESWC, Portoroz, Slovenia 27

28 User Community and Evaluation (2/2) Online Questionnaire: USE* questionnaire: values ranging from 1 to 7 Lund, A.M. (2001) Measuring Usability with the USE Questionnaire. STC Usability SIG Newsletter, 8:2. collected 11 anonymous responses USE Values Feature Evaluation easy to use effective interesting History 5,38 5,50 6,33 SPARQL Querying 4,00 5,40 6,29 Usefulness Ease of use Ease of learning Satisfaction Global 5,34 4,49 5,11 4,93 Experienced 5,58 4,66 5,18 5,02 Inexperienced 4,97 4,19 5,00 4,79 Publication Workflow Management Collaborative Management 5,50 5,63 6,22 5,75 5,88 6,11 Scheme Management 4,83 5,17 5,57 Role-based Access Control 5,33 5,22 5,40 Reasoning 4,29 4,43 5,38 Triple Store Connectivity 3,67 4,50 5,00 03/06/ th ESWC, Portoroz, Slovenia 28

29 Why should I "buy" it? Collaborative Management Validation&Publication Workflow (propose, validate, publish, revise, deprecate ) Fine grained user management both users and functionalities may be associated in groups" Functionalities (or groups of) may be assigned to different users (or groups of) Full editing history (not only concepts, but most of the actions can be subject to validation too) RSS Feeds Fine-grained metadata and editorial notes: SKOS-XL and reified definitions allow for timestamped status and rich editorial notes Multilinguality Strong support for multi-lingual thesauri management Application itself is also multilingual (currently support for english, dutch, spanish, more languages coming) Native RDF support Support for different triple stores Possibilty to SPARQL query/update through a dedicated interface with syntax completion/highlight SKOS-XL management If preferred, SKOS-core export through available conversion tools Large scale thesauri management Scalability limited only by the underlying triple store Extensibility OSGi connectable services Advanced skos:conceptscheme Management SKOS allows for non-trivial management of multiple conceptual schemes, which is fully supported by VB And, last but not the least: Free and Open Source! ( 03/06/ th ESWC, Portoroz, Slovenia 29

30 Future works A more dynamic framework for content validation Trade-off between extensibility/flexibility and the strong controlled approach ICV: more checks (available from the ST engine) Overcome extensibility limitations of GWT More interaction with the Linked Data Improved Alignment Generation of VoID / LIME descriptions 03/06/ th ESWC, Portoroz, Slovenia 30

31 Contacts VocBench site: VocBench You can also follow VB by registering to: AIMS Community Site: (you can selected the topics you are interested into) VocBench Mailing Lists: User: Developer: Semantic Turkey Mailing Lists: User: Developer: 03/06/ th ESWC, Portoroz, Slovenia 31

32 03/06/ th ESWC, Portoroz, Slovenia 32/XX

33 TIME FOR QUESTIONS :-) oh, and there s a demo tomorrow! 03/06/ th ESWC, Portoroz, Slovenia 33