Contextual Linking Architecture Christophe Blanchi June Corporation for National Research Initiatives Approved for Public Release © 2006 CNRI.

Corporation for National Reserch InitiativesCorporation for National Research Initiatives Background CNRI developed the Contextual Linking Architecture as part of the DVIA Registry project for the Defense Technical Information Center (DTIC). The DVIA Registry System provides contextual search, navigation and access for DTICs Technical Reports. The DVIA Registry and the Contextual Linking Service leverages CNRIs handle system, Digital Object Architecture and OpenURLs. The DVIA Registry currently contains about Technical Report metadata and is used by DTIC as a technology demonstrator. Approved for Public Release © 2006 CNRI.

Corporation for National Reserch InitiativesCorporation for National Research Initiatives DVIA and ADL-R Similarities Same general requirements Distributed, service oriented metadata registry that is to provide search, discovery, and access to metadata and the resources it describes. Same technical roots Use of CNRI Digital Object Architecture as a storage abstraction. Extensive use of Handles Resources and services identification. Authentication and Authorization of registrants. Standardized, distributed system for registration of metadata. Distributed Indexing Service. Approved for Public Release © 2006 CNRI.

Corporation for National Reserch InitiativesCorporation for National Research Initiatives DVIA and ADL-R Differences Different Metadata and Data Requirements ADL-R was required to support two types of XML metadata: LOM and CORDRA repository metadata. The DVIA registry was required to support any type XML metadata that are instances of DVIA registered XML schemas and arbitrary data. Different Registration Requirements ADL-R registration process requires tight validation enforcement. DVIAs registration process validation are not as specific. Different Search and Access Requirements ADL-R provides a simple search and access to its metadata. DVIA provides contextualized search and access to its registered resources. Different Federation Requirements ADL-R provides a hierarchical federation model. DVIA supports an extensible federation model. Approved for Public Release © 2006 CNRI.

Corporation for National Reserch InitiativesCorporation for National Research Initiatives DVIA Registry System Architecture DVIA Registry and other services DVIA Registry and other services OAI-PMH Server Interface OAI-PMH Server Interface OAI-PMH Client Interface OAI-PMH Client Interface Handle System Registration Interface Registration Interface DVIA Web Interface DVIA Web Interface Administrative Interface Administrative Interface Contextual Linking Service Contextual Linking Service To other registries To other Contextual Linking Services Approved for Public Release © 2006 CNRI.

Corporation for National Reserch InitiativesCorporation for National Research Initiatives DVIA Registry Federations DVIA Registries can harvest metadata from other registries. –Enables a given registry to mirror one or more registries. –Registries use OAI-PMH to publish and acquire metadata from each other. DVIA Registries can create federations of registries. –Federated registries behave as single unified registry and are uniquely identified by a handle. –The Context Linking Service can route queries addressed to the federation to the appropriate registry based on federation rules. DVIA Registries can act as a registry of registries by indexing registry level metadata. –Clients can search a registry of registries to choose which registry or registry federation to issues their queries. Approved for Public Release © 2006 CNRI.

Corporation for National Reserch InitiativesCorporation for National Research Initiatives Federated Systems Federation A Federation B User Issues a query to Federation A Federation A routes the query to the proper registry User Query for federation level information Issues a query to federation B Federation B routes the query to the proper registry Federation of Federations Approved for Public Release © 2006 CNRI.

Corporation for National Reserch InitiativesCorporation for National Research Initiatives Contextual Linking Service The Contextual Linking Service (CLS), acts on behalf of clients to issue searches, retrievals, and other requests against a targeted registries and services. All requests to the CLS are expressed as OpenURLs (NISO Z39.88). An OpenURL expresses the relationship between who is making what request, from where, to which registry, to what resource, and in which CLS context. Each of these entities is identified with a unique handle. The CLS processes all queries and returns results that are appropriate given the registrys and users respective contexts. The CLS processes the results to impart context, when appropriate, by generating and embedding OpenURL links within a querys results. The CLS processes its queries and results based on rules implicitly referenced by each of the OpenURL entities handle. The CLS are not location specific. Approved for Public Release © 2006 CNRI.

Corporation for National Reserch InitiativesCorporation for National Research Initiatives Contextual Linking Service OpenURL Parse OpenURL Acquire the processing rules by resolving the handles in the OpenURL entities. Handle System Contextual Linking Service Approved for Public Release © 2006 CNRI.

Corporation for National Reserch InitiativesCorporation for National Research Initiatives Contextual Linking Service OpenURL Evaluate requestor authorization based on rules referenced by the OpenURL entities. Parse OpenURL Handle System Contextual Linking Service Approved for Public Release © 2006 CNRI. Pre-Process Request

Corporation for National Reserch InitiativesCorporation for National Research Initiatives Contextual Linking Service Pre-Process Request OpenURL Parse OpenURL Handle System Distributed Services Distributed Resources Issue the service request as specified in the OpenURL service entity. Contextual Linking Service Approved for Public Release © 2006 CNRI. Perform Service Requests

Corporation for National Reserch InitiativesCorporation for National Research Initiatives Contextual Linking Service Perform Service Requests Pre-Process Request OpenURL Parse OpenURL Handle System Distributed Services Distributed Resources Contextual Linking Service Approved for Public Release © 2006 CNRI. Process results returned by the target service according to OpenURL entities rules. Contextualized XML Results Post Process Results

Corporation for National Reserch InitiativesCorporation for National Research Initiatives Request Contextualization User A, Music Group Member User A, issues a search for music by artist name The CLS evaluates the request and generates appropriate query results 1. Album 1 Search Results 2. Album 2 4. Album 4 Members Only 3. Album 3 User B User B issues the same search as user A Album 1 Track 1 Track 2 Track 3 Track 4 WMP Full Version 1. Album 1 Search Results 2. Album 2 3. Album 3 The CLS evaluates the request and generates appropriate query results Album 4 Track 1 Track 2 Track 3 Track 4 WMP Full Version Approved for Public Release © 2006 CNRI. Album 1 Track 1 Track 2 Track 3 Track 4 WMP RP 20s Full length track First 20 seconds

Corporation for National Reserch InitiativesCorporation for National Research Initiatives Request Contextualization User A, Music Group Member 1. Album 1 Search Results 2. Album 2 4. Album 4 Members Only 3. Album 3 User B Album 1 Track 1 Track 2 Track 3 Track 4 WMP Full Version Approved for Public Release © 2006 CNRI. Full length track First 20 seconds The CLS evaluates the OpenURL knowing that User B is making the request User A shares the link to track 3 with User B. OpenURL

Corporation for National Reserch InitiativesCorporation for National Research Initiatives Request Contextualization User A (Service Member) User A issues a search for quantum computing User B (Non Service Member) User B issues the same search as user A The Linking Server applies rules and generates appropriate search results for User A. 1. Quantum Computing Introduction Search Results 2. Quantum Computing Error Correction 4. Quantum Cryptography 5. Quantum Entanglements 6. General Nano Computing 3. Quantum Superposition Full Article Forward Author links Quantum Computing Error Correction 1. Quantum Computing Introduction Search Results 2. Quantum Computing Error Correction 4. Quantum Cryptography 5. Quantum Entanglements 3. Quantum Superposition Approved for Public Release © 2006 CNRI. Full Article Quantum Computing Introduction Article Abstract Quantum Computing Introduction

Corporation for National Reserch InitiativesCorporation for National Research Initiatives Request Contextualization User A (Service Member) User B (Non Service Member) 1. Quantum Computing Introduction Search Results 2. Quantum Computing Error Correction 4. Quantum Cryptography 5. Quantum Entanglements 6. General Nano Computing 3. Quantum Superposition The CLS generates appropriate results for User A. Full Article Forward Author links Quantum Computing Error Correction Approved for Public Release © 2006 CNRI. User A shares the OpenURL with User B OpenURL Document Access Denied The CLS generates appropriate results for User B.

Corporation for National Reserch InitiativesCorporation for National Research Initiatives OpenURL and Application Profiles Referring Entity Referent Requester Service Type Resolver Referrer Entities Open URL Entity Identifier: handle Metadata: in-line/by-ref Private Data: Profile specific Entity Descriptors Entity HDLApplication Profile Application Profiles/Processing Rules HDLApplication Profile Entity Identifier: handle Metadata: in-line/by-ref Private Data: Profile specific Entity HDLApplication Profile HDLApplication Profile Entity Identifier: handle Metadata: in-line/by-ref Private Data: Profile specific Entity HDLApplication Profile HDLApplication Profile Entity Identifier: handle Metadata: in-line/by-ref Private Data: Profile specific Entity HDLApplication Profile HDLApplication Profile Entity Identifier: handle Metadata: in-line/by-ref Private Data: Profile specific Entity HDLApplication Profile HDLApplication Profile Entity Identifier: handle Metadata: in-line/by-ref Private Data: Profile specific Entity HDLApplication Profile HDLApplication Profile Approved for Public Release © 2006 CNRI.

Corporation for National Reserch InitiativesCorporation for National Research Initiatives OpenURL and Application Profiles Entity Handle OpenURL Entity Resource Information Location Information Resource Attributes Entity Processing Rules and Standards Processing Rules Resolvers Processors Input Data Standards Code Output Data Standards Rules Description Application Profile Resolves Approved for Public Release © 2006 CNRI.

Corporation for National Reserch InitiativesCorporation for National Research Initiatives Questions? Approved for Public Release © 2006 CNRI.

Corporation for National Reserch InitiativesCorporation for National Research Initiatives DVIA and ADL-R Differences Different Metadata Requirements ADL-R was required to support two types of XML metadata: LOM and CORDRA repository metadata. The DVIA registry was required to support any type XML metadata that are instances of registered XML schemas. Different Data Requirements ADL-R was required to register metadata only. DVIA was required to register metadata and data of any complexity. Different Access Requirements ADL-R provides a simple search and access to its metadata. DVIA provides contextualized search and access to its registered resources. Different Federation Requirements ADL-R provides a hierarchical federation model. DVIA supports an extensible federation model. Approved for Public Release © 2006 CNRI.