The long-term technological objective for the Cooperative is a platform that will support a continuously expanding, curated corpus of reliable biographical descriptions of people linked to and providing contextual understanding of the historical records that are the primary evidence for understanding their lives and work. Building and curating a reliable social-document corpus will involve a balanced combination of computer processing and human identity verification and editing. The next step towards realizing the long-term objective is to transition from a research and demonstration project to a production web service. From a technical perspective, this means transitioning from a multistep human-mediated batch process to an integrated transaction-based platform. Instead of the data being passed along from one programmer to another, the architecture will automate the flow of data in and out of the different processing steps by interconnecting the processing components, with events taking place in one component triggering related events in another. For example, the addition of a new descriptive record will lead to automatic updating of graph data in Neo4J and updating the indexed data in the History Research Tool. The coordinated architecture will support both the batch ingest of data and human editing of the data to verify identities and refine and augment the descriptions over time.
Using techniques developed in the research and demonstration phase of SNAC, computer processing will be used to extract and ingest existing name authority and biographical data from existing archival descriptions. Identity reconciliation, i.e. matching and combining two or more descriptions for the same person, organization, or family, has relied solely on algorithms in the research phase. While identity reconciliation techniques will continue to inform the reconciliation process, Cooperative professional editors, beginning with librarians and archivists though expanding over time to include allied scholars, will verify identities and curate the data. This two faceted approach, combining intelligent computer processing and professional editing, will enable building a large corpus of networked social-document data that is not constrained geographically or by historical period, and over time establishes an expanding core of reliable identities within the overall corpus. (See Appendix 4 for a diagram showing the relationship between certain/uncertain data and dense/sparse evidence for identity resolution.)
###Current SNAC R&D Technology Platform
###Current SNAC R&D Technology Platform
Current SNAC processing employs a complex sequence of steps that produces a collection of biographical descriptions used to produce the History Research Tool.
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@@ -19,7 +19,7 @@ Current SNAC processing employs a complex sequence of steps that produces a coll
Transforming the existing platform into a platform that supports both ingesting of large batches of data but also manual maintenance of the data will require a reconfiguration of major components of the current underlying technology. Two major existing components will be retained with minimal modification during the pilot: the "back end," the processing used to extract data from existing descriptive sources and assemble it into EAC-CPF instances; and the "front end," the History Research Tool. While the code and technology for these two components of the SNAC infrastructure would benefit from additional development and refinement, each is sufficiently robust and functionally complete to remain largely unchanged during the pilot. The intermediate technologies used in loading and matching of the EAC-CPF will need to be thoroughly revised, retaining existing functionality but in a configuration that will support both batch and manual maintenance. One component, the processes used to merge or combine matching EAC-CPF instances will be deferred to a later stage of development (to be described below). Finally, two components that will be developed in the pilot are entirely new: an API to support both batch processing and an Editing User Interface, and development of the Editing User Interface itself. While the transformation of the underlying technology is underway, there will be a one-year pause in batch ingesting new data in order to focus programming resources on the essential development work needed to go forward. No large batches of new source data have been solicited for the pilot, although pilot member institutions will contribute batches of data for use in first testing and then bringing online the batch ingest function of the Cooperative. During the pilot, new sources of batch data will be solicited for the second two-year phase of establishing the Cooperative.
###Data Maintenance Store
###Data Maintenance Store
In the current processing stream, the EAC-CPF instances are placed in a read-only directory as the primary data store. A small number of select components (name strings) of each EAC-CPF XML-encoded instance are loaded into a PostgreSQL database. In order to support dynamic manual editing of the EAC-CPF instances, it will be necessary to parse the entirety of each EAC-CPF instance into PostgreSQL tables.2 Parsing all (or most) components of the EAC-CPF instances into SQL tables is necessary because no open source native XML database will efficiently support the essential maintenance functionality required, in particular effectively managing editing transactions at the component-level of each EAC-CPF instance.3 MarkLogic would enable maintaining the data in XML, but it is an expensive commercial platform. The most robust of the open source native XML databases, eXist, does not support transaction management. Further, EAC-CPF was not designed as a maintenance format, but rather as a communication format and, with this in mind, was intentionally designed to facilitate the serialization of the data into and out of SQL environments.4
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Merge processing, that is the automatic merging or combining of EAC-CPF instances deemed reliably to be for the same identity, will be deferred until after the revision of the match processing and developing an effective quality evaluation regimen. The current merge processing combines two or more EAC-CPF instances into one. The combining is primarily cumulative, though redundant data fields are combined as a further step. Once human verification and editing is introduced, any automatic merging of records will necessarily need to respect the integrity of the judgment of the human editors. The merge algorithms will need to be based on policies developed in consultation with the Cooperative community, taking into account quality evaluation findings and the nature of the components of each description. The engagement of the archivists and librarians thus will be essential in developing an appropriate balance of computer and human maintenance of the data. An informed understanding of the issues will not be possible until the editing platform and editing interface are functional, and the community knowledgeably engaged.
###Editing User Interface
###Editing User Interface
Developing the Editing User Interface (EUI) is a primary objective of the two-year pilot. The SNAC developers have identified the essential functional requirements for the interface, and extensive user studies with archivist and librarians have been used to refine and substantially extend the requirement list. Because the EUI is dependent on the reconfiguration and development of the data maintenance and identity reconciliation modules, and the development of the Edit API, the development will first focus on engaging the pilot participants by means of wireframes of the EUI, in conjunction with rehearsing established research and description tasks, the order or orders in which such task are performed, and walk-throughs of the steps involved in manually adding, revising, merging, and splitting identity descriptions. These activities and the findings that result from them will inform the parallel development of the maintenance platform. When the underlying data maintenance platform is in place, development of the EUI will commence, informed by the activities described above. As the EUI becomes functional, the pilot participants will transition to iteratively testing and using it to perform editing tasks to ensure that the essential functions are supported and that this support makes the performance of the tasks logical and efficient. Those functions of the EUI that overlap with the History Research Tool will employ a common interface. The bulk of the EUI will be based on JavaScript running in modern web browsers.
###Graph Data Store – Visualizations and Exposure of RDF/LOD
###Graph Data Store – Visualizations and Exposure of RDF/LOD
Neo4J, an open source graph database, is currently used to generate social-document network data as GraphML. The generated GraphML supports the graphic representations of the social-document network in the History Research Tool. In addition, it supports exposure of the SNAC data for third-party use through Resource Description Framework (RDF) Linked Open Data (LOD). The Neo4J component will not require major reconfiguration during the pilot, but will be used as an active source of the social-document network data in place of static GraphML representation. In this capacity, the Neo4J database will provide a number of services: serving graph data to drive social-document network graphs in the HRT; and serving and providing LOD through a SPARQL endpoint and RDF exports for third-party consumption. It will, however, be necessary to integrate both the data ingest and data serving functionality of Neo4J into the coordinated system architecture in order to ensure that the graph data and dependent services remain current with the evolving SNAC data.
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Currently there is no existing ontology for archival description, and thus the classes and properties used in exposing graph data expressed in RDF is based on classes and attributes selected from existing, well-known and widely used ontologies and vocabularies: Friend of a Friend, OWL, SKOS, Europeana Data Model (EDM), RDA Group 2 Element Vocabulary, Schema.org, and Dublin Core elements and terms.9 In the long term, it should be noted that the International Council on Archives' Expert Group on Archival Description (EGAD; chaired by the PI) is developing an ontology for archival entities and the description thereof. While the initial focus of EGAD necessarily is focused on developing a clear model of the world based on archival curatorial principles, once this work is completed, the group intends to collaborate in mapping the archival ontology to CIDOC CRM, which incorporates both museum and library description.10
###Component Subsystem Integration
###Component Subsystem Integration
In order to integrate the component subsystems of the Cooperative technological platform we will develop a thin middleware component that routes each request from a client or from an intra-server process to the appropriate individual subsystem based on SNAC workflows we will establish. The middleware component invokes the required functions via calls to the subsystems: Identity Reconciliation, PostgreSQL database, Neo4J graph database, History Research Tool, and Editing User Interface. These subsystems deal with the variety of automated and semi-automated transactions required by the Cooperative platform.
