An eGovernment system for temporal- and semantic-aware access to norms

1. SWEG 2006 – The Semantic Web meets eGovernment 2006 AAAI Spring Symposium Series, Stanford University, CA, March 2006 An eGovernment system for temporal- and semantic-aware access to norms Federica Mandreoli Riccardo Martoglia Enrico Ronchetti Paolo Tiberio Università degli Studi di Modena e Reggio Emilia Fabio Grandi Maria Rita Scalas Università degli Studi di Bologna

2. Overview • Our research activities concern the implementation of Web information systems for eGovernment applications • Development of eGovernment initiatives: more and more on-line resources and services are being made available by Public Administrations (PAs) • We make use of temporal database and semantic Web techniques to provide personalized access to such resources and services • In particular, we consider multi-version norm texts (stored in XML format) available in Web repositories SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms

3. new version new version Original normative text time 1 2 3 Importance of versioning • Temporal concerns are ubiquitous in the law domain • Each normative text changes in time due to different modifications, but keeps its identity • The ability to model temporal dimensions is essential for the management of evolving norms • it is crucial to reconstruct the consolidated version of a norm • also past versionsare still important SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms

4. Importance of versioning • Applicability (semantic) versioning also plays an important role • some norms or some of their parts have or acquire a limited applicability • personalized versionof the norm • A version only containing articles which are applicable to a citizen’s personal case Art. 1 (unemployed) xxy yyx yxyx yyyxx xyyx Art. 2 (self-employed) aab bbab abab abba ab Art. 3 (retired) qwqq ww wqqw wq ww Self-employed SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms

5. Motivation • Large XML collections of norms are made available by the PA on the Web but personalizationis: • Absent, e.g. http://www.normeinrete.it(temporal versioning partially supported) • Predefined in the Website structure and contents, e.g. http://www.italia.gov.it(hardwired by human experts following the life-events approach) • Lack of an effective, flexible, on-demand (“intelligent”, efficient) personalization facility SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms

6. Objectives • Development of an effective and efficientWeb information system where: • norms are represented as XML documents • dynamics of norms in time is captured • limited applicabilityof norms (and their parts) is captured • selective access and reconstruction of versionsis supported by a query engine • Aimed at: • enabling citizens to access personalizedversions of multiversion resources • improving and optimizing the involvement of citizens in the eGovernance process SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms

7. Personalized access to multi-version norms SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms

8. XML REPOSITORY OF ANNOTATED NORMS 3 Querying phase The Technological Infrastructure Public Administration DB WEB SERVICES OF PUBLIC ADMINISTRATION 1 WEB SERVICES WITH ONTOLOGY OC 2 SIMPLE ELABORATION UNIT creation /update classCx 1 – identification phase: reconstruction on-the-fly of the digital identity of the authenticated user 2 – classification phase: use of the collected digital identity to classify the citizen with respect to the civic ontology Oc 3 – querying phase: access and reconstruction of all and only norms which are applicable to the class Cx SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms

9. Approach • Definition of a temporal XML model including • a temporal multi-version XML schema • is based on the hierarchical organization of normative texts: contents-section-article-paragraph • at each level of the hierarchy, the history of changes is represented by the (time-stamped) versions produced • it supports ancestor-descendant inheritance • temporal manipulation operations • Extension of the XML model with applicability annotations in order to support semantic versioning • Design, implementation and evaluation of system prototypes supporting the model SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms

10. Vt_Start – R Vt_End – O Tt_Start – R Tt_End – O Et_Start – R Et_End – O Vt_Start – R Vt_End – O Tt_Start – R Tt_End – O Et_Start – R Et_End – O Vt_Start – R Vt_End – O Tt_Start – R Tt_End – O Et_Start – R Et_End – O Vt_Start – R Vt_End – O Tt_Start – R Tt_End – O Et_Start – R Et_End – O TA TA TA TA Publication – R Vt_Start – R Vt_End – O Tt_Start – R Tt_End – O Et_Start – R Et_End – O The temporal XML schema Num – R Law Type – R 4 Temporal Dimensions: Publication time time of publication on the Official Journal Validity time time the norm is in force Efficacy time time the norm can be applied Transaction time time the norm is storedin the system Title Contents An_ref – O Ver Num – R Section Num – R An_ref – O Ver Num – R Num – R Heading Article An_ref – O Ver Num – R Heading Paragraph Num – R An_ref – O Ver Num – R SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms

11. Semantic versioning • Extension of the multi-version model based on temporal dimensions to include a semantic versioning dimension to provide personalized access to norm texts • Civic ontology: a classification of citizens based on the distinctions introduced by successive norms (founding acts) that imply some limitations in their applicability SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms

12. Semantic versioning • At this stage of the project, we manage “tree-like” ontologies • class taxonomies induced by the IS-A relationship • we exploit the pre-order and post-order properties of trees • New versioning dimension: applicability of different parts of a norm text to the relevant classes of the civic ontology • Applicability annotations (AA) are added to semantic versions SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms

13. Semantic versioning • Applicability is inherited by descendant nodes unless locally redefined • By means of redefinitions we can also introduce, for each part of a document, complex applicability properties • Restrictions with respect to ancestors • Extensions with respect to ancestors SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms

14. Example of full search • John Smith is a self-employed citizen. • He is interested in the text of all the norms ... • ... which contain paragraphs dealing with health care, ... • ... which were valid and in effect between 2002 and 2004, ... • ... and which are applicable to his case (civic class 7). Structural constraint Textual constraint Temporal constraint Applicability constraint 4 orthogonal constraints SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms

15. Example of full search FOR $a IN norms WHERE textConstr ($a//paragraph//text(), ’health AND care’) AND tempConstr (’vTime OVERLAPS PERIOD(’2002-01-01’,’2004-12-31’)’) AND tempConstr (’eTime OVERLAPS PERIOD(’2002-01-01’,’2004-12-31’)’) AND applConstr (’class 7’) RETURN $a Structural constraint Textual constraint Temporal constraint Applicability constraint 4 orthogonal constraints SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms

16. Example of full search Civic ontology Normative DB Norm Article 1 Article 2 TA Ver 1 AA=3 Par 1 Par 2 … norm//paragraph//text() … TA TA TA Ver 1 Ver 1 Ver 2 AA=4 AA=3,8 ‘class 7’ … AA Health care… …text X Public health… …text Y Health care… …text Z SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms

17. Enhanced query processing efficiency Reduced memory requirements Our prototype system (“native” approach) • The query engine is able to access and retrieve only the strictly necessary data • selection relies on ad-hoc data structures supporting multi-versioning • storage granularity is finer than the entire documents used by standard XML engines • Only the parts which satisfy the temporal and applicability constraints are used for the reconstruction of the retrieved documents • There is no need to retrieve whole XML documents and build space-consuming structures such as DOM trees SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms

18. Three XML document sets 5000 documents (120MB) 10000 documents (240MB) 20000 documents (480MB) Variable document size min = 2KB avg = 24KB max = 125KB PERSONALIZATION OF THE QUERIES Evaluation benchmark • Five different query types • Queries on keywords (structural + textual constraints) • Q1 – keywords in contents • Q2 – keywords in type and contents • Temporal queries (structural + temporal constraints) • Q3 – conditions on publication, validity and transaction time • Mixed queries (structural + textual + temporal constraints) • Q4, Q5 – with keywords and temporal conditions • Five variants with semantic constraints • Qx-A – with additional applicability constraints SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms

19. Performance evaluation • Very high personalization query efficiency • The system is able to solve personalization problems by means of simple comparisons involving pre-post encodings • 0.5-1% more time than for the original versions • 3-4%storage space overhead SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms

20. Performance evaluation time 1741 msec 1366 msec 1046 msec 5000 docs 10000 docs 20000 docs • Scalability tests • The computing time grows sublinearly with the number of documents • Good scalability of the system in every type of query context SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms

21. Conclusions • We presented our research work concerning the design and implementation of efficient Web-based information systems for eGovernment applications • We introduced a personalized access to resources on the basis of the digital identity of citizens relying on semantic versioning and ontology mapping • We developed a efficient platform (“native” approach) for which a specialized Multi-version XML Query Processor has been designed and implemented • We proved our approach to be very efficient in a large set of experimental situations and showed excellent scale-up figures with varying load configurations SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms

22. Future Work • Extensions of the current framework • more advanced application requirements may include a more sophisticated ontology definition, possibly versioned, and more advanced reasoning services • Development of a complete technological infrastructure usable in a large Web-based eGovernment scenario, including • identification, classification and reconstruction services • Assessment of our prototype systems in a concrete working environment • with real users and with a large repository of real norms • Extension to a more general application domain(Web personalization via ontology-based user profiling) SWEG 2006 An eGovernment system for temporal- and semantic-aware access to norms