standOff. When we have changed our mind. Some entries in the table begin with a word in capitals and the reason for it. EVIDENCE CORRECTED — the finding still stands, but we had quoted the wrong sentence from the paper, and the quotation has been replaced with the right one. RETRACTED — the entry itself was wrong; it stays on the page, marked, with the reason, rather than being deleted. WITHDRAWN AND REPLACED — the entry was wrong, and a corrected version of it appears in the entries below. Each mark carries its own reason, in brackets, because the reasons differ from one entry to the next. An entry we have WITHDRAWN is removed from this page and kept in the record, with its reason. A line reading Audit and a date is a later re-reading of the entry against its whole sentence: DOUBTFUL means it was kept, and the reason says what is loose about it. Quotation marks inside the tagger's sentence. Where a tag is the tagger's own sentence, a phrase in quotation marks inside it is borrowed from the paper — the tagger's wording around it is not. The paper's own sentence is the evidence quote shown on the same row, so the borrowing can be checked against the thing borrowed from without leaving this page. Nothing inside quotation marks anywhere on this page is ours: if it is quoted, it is the paper's. Whose words a concept carries. A concept entry records a term the paper itself uses, so the term, the sense given for it, and its evidence are the paper's own words, quoted where the paper fixes them. This is the opposite of a sense entry in the tag table, which is the tagger's sentence about how the paper uses a term. Where a concept entry could not be grounded in the paper's words, the entry says so on its own row.| relation to other work | claim_relations | how this paper stands to another: agrees, contradicts, extends, qualifies |
| claim type | claim_type | the shape of the claim: existence, mechanism, method, critique, prediction, null |
| concept edge | concept_edges | an asserted relation between two concepts, with the sentence asserting it |
| concept | concepts | an idea the paper works with, quoted where the paper uses it |
| content tag | content_tags | a finding, definition, quantity, statistic or variable named in the paper |
| contribution | contribution | what the paper claims to add |
| limitation | limitations | what the paper says its evidence cannot support |
| mechanism | mechanisms | how the reported effect is said to come about |
| method | method | how the paper produced its evidence |
| object of study | object_of_study | what the paper is about — the thing it investigates |
| phenomenon | phenomenon | the effect or regularity under study |
| research question | research_question | the question the paper sets itself |
| sense | senses | a distinct use of a term, quoted where the paper fixes it |
| unrecordable relation | unhoused_relations | a relation the paper asserts that this vocabulary cannot express, with the reason |
The reference list is not part of the text we hold for this paper. Our copy was extracted from the publisher's page and the bibliography did not survive that extraction, so the article below ends before its references. Nothing has been removed by us.
Darwin Core: An Evolving Community-Developed Biodiversity Data Standard
Abstract
object_of_studyclaim_typemechanisms↗concepts↗concepts↗concepts↗concepts↗concepts↗concepts↗unhoused_relationsclaim_relationsBiodiversity data derive from myriad sources stored in various formats on many distinct hardware and software platforms. An essential step towards understanding global patterns of biodiversity is to provide a standardized view of these heterogeneous data sources to improve interoperability. Fundamental to this advance are definitions of common terms. This paper describes the evolution and development of Darwin Core, a data standard for publishing and integrating biodiversity information. We focus on the categories of terms that define the standard, differences between simple and relational Darwin Core, how the standard has been implemented, and the community processes that are essential for maintenance and growth of the standard. We present case-study extensions of the Darwin Core into new research communities, including metagenomics and genetic resources. We close by showing how Darwin Core records are integrated to create new knowledge products documenting species distributions and changes due to environmental perturbations.
Introduction
Concern over global loss of biodiversity [1] – [5] has resulted in widespread demand for quick, reliable access to high-quality data on the spatio-temporal occurrence of species and their relation to the environment. Initial studies have documented the response by species to diverse agents of environmental change [6] – [7] , including alarming vertebrate extinctions [8] . The signature of climate and other environmental changes and their effects on biodiversity is now well documented, and the evidence is overwhelming [9] – [14] .
limitationsThe documentation of global patterns of biodiversity change is an important first step toward a wise, sustainable policy of conservation and management in the face of a changing environment [15] . Such documentation has emerged as a global priority [16] – [18] . A major impediment to creating this documentation is the lack of easily accessible data at the scope and at the scales needed. Most studies documenting biodiversity changes are limited to a few well-studied species or to small temporal and spatial scales [19] . To make effective use of existing data for broad-scale analyses, community coordination is required. Information must be in digital form, accessible, discoverable, and integrated. Each of these criteria presents distinct challenges, some of which are unique to biodiversity-related data.
phenomenonlimitationsconcepts↗concepts↗concepts↗concepts↗unhoused_relationsunhoused_relationscontent_tagsA general challenge of biodiversity data that is shared with many other information domains is the lack of a coordinated publishing and integration system; data repositories tend to be isolated from each other in the absence of standards for data and communication protocols. Heterogeneity in meaning and content of terms creates obstacles in every aspect of data integration and use, including discovery, comparison, and quality assessment. Information communities, especially Library Information Sciences, have a long history of meeting these challenges through the creation and maintenance of standards.
concepts↗concepts↗concepts↗unhoused_relationssensesconcept_edgescontent_tagscontent_tags↗content_tagscontent_tagscontent_tagsDarwin Core [20] is a standard for sharing data about biodiversity – the occurrence of life on earth and its associations with the environment. Darwin Core first emerged around 1999 as a loosely defined set of terms, and progressed through several iterations by different groups resulting in many different variants [21] . A formal set of terms and processes to manage changes were necessary to ensure utility for data integration. These aspects were developed within the Darwin Core Task Group [22] of the Taxonomic Databases Working Group (TDWG; www.tdwg.org ) and ratified as a standard in October 2009. The philosophy for Darwin Core development has been to keep the standard as simple and open as possible and to develop terms only when there is shared demand. Darwin Core has a relatively long history of community development and is deployed widely [23] – [24] . For example, the Global Biodiversity Information Facility currently indexes approximately 300 million Darwin Core-formatted records published by more than 340 organizations in 43 countries. Increasingly, Darwin Core is being incorporated in communities beyond that of natural history collections ( Figure 1 ), in which the standard has its roots.
Scope of Darwin Core: The Standard, deriving from previous standards work (e.g., Dublin Core), describes core sets (e.g., organismal, taxonomic) of characteristics of biodiversity, which are applicable in many biological domains (e.g., Paleontology, Botany). The standard can be extended to cover details of specific sub-disciplines (e.g., Genetic Resources, Herbaria, Taxonomic Checklists). Collaborations with other standards organizations (Genomics Standards Consortium (GSC) extend Darwin Core for new disciplines (Genomics, Metagenomics, Gene Marker Sequences.
research_questioncontributionIn this paper, we describe the Darwin Core standard, its history, status, relationship to other standards, and prospects for further evolution. We also discuss how data sets are brought into Darwin Core compliance and how Darwin Core records are currently shared in a distributed publishing platform. We will demonstrate how Darwin Core continues to extend beyond its original formulation for natural history collections and will present, via use cases, how the standard continues to be reshaped and extended through new collaborations. We close by discussing innovative computational and informatics approaches to improving the scale, scope, and usability of networks that rely on Darwin Core compliant records.
Methods
Defining Darwin Core
mechanisms↗limitationsconcepts↗unhoused_relationsThe primary purpose of Darwin Core is to create a common language for sharing biodiversity data that is complementary to and reuses metadata standards from other domains wherever possible. Creating this common language has been particularly challenging, since natural history data curation practices have been developed locally and organically over hundreds of years, have varied between disciplines as well as institutions, and have had limited culture of data sharing.
mechanisms↗concepts↗concepts↗concepts↗concepts↗concepts↗unhoused_relationssensesconcept_edgescontent_tagscontent_tagscontent_tags↗content_tags↗Fundamentally, Darwin Core is a set of terms having clearly defined semantics that can be understood by people or interpreted by machines, making it possible to determine appropriate uses of the data encoded therein. The terms are organized into nine categories (often referred to as “classes”, Figure 2 ), six of which cover broad aspects (event, location, geological context, occurrence, taxon, and identification) of the biodiversity domain. The remaining categories cover relationships to other resources, measurements, and generic information about records. Especially for the record level, Darwin Core recommends the use of a number of terms from Dublin Core (type, modified, language, rights, rightsHolder, accessRights, bibliographicCitation, references). The full set of current Darwin Core terms with their descriptions is available in the Quick Reference Guide ( http://rs.tdwg.org/dwc/terms/ ).
limitationsconcepts↗concepts↗concept_edgescontent_tagscontent_tags↗content_tagscontent_tagscontent_tagscontent_tagsDarwin Core Categories: Simple Darwin Core is comprised of seven categories of terms (green). This subset of Darwin Core terms represents descriptive data about organisms that can be represented in one file with one row per record and one column per term. Two additional categories (orange) expand Darwin Core with concepts that require a more complex data structure, such as multiple measurements from a single specimen, and cannot be represented easily in Simple Darwin Core.
concepts↗concepts↗concepts↗concept_edgesThe authoritative form of the Darwin Core is a downloadable archive [25] , which contains various documents that are also available via web pages ( http://rs.tdwg.org/dwc/ ). Key among the documents is http://rs.tdwg.org/dwc/rdf/dwctermshistory.rdf . This document includes descriptions of all terms, their histories, the relationships among them, and the relations between them and terms from other standards, all in a single file. The document is written in the Resource Description Framework (RDF) format, which is a standard for encoding the semantic structure of web-based resources. The same information is rendered in human-readable form on web pages (Quick Reference Guide, Type Vocabulary, Complete History, Mapping to ABCD, and Mapping to Old Versions). The standard also includes recommendations for implementation ( Introduction , Simple Darwin Core, XML Guide, and Text Guide), a document describing how the standard is to be maintained (Namespace Policy), and a document describing the rationale behind any changes that are made to the standard (Decision History). In addition to the authoritative standard, Darwin Core consists of non-normative documents, commentaries, and tools tracked separately ( http://code.google.com/p/darwincore/ ).
concepts↗claim_relationsconcept_edgesThough the scope and governance of Darwin Core are distinct from Dublin Core [26] , readers will recognize the ancestry of Darwin Core in their shared traits: mission, principles of operation, and inherited terms. Indeed, if words were nucleotides, the Darwin Core mission is the same as that of Dublin Core except for one base-pair addition (in bold), namely, “to provide simple standards to facilitate the finding, sharing and management of biodiversity information.” This relationship is not accidental. The Dublin Core Metadata Initiative (DCMI) has done a very good job of maintaining the metadata specifications at the core of web-based resources. The success of DCMI encouraged TDWG to adopt similar policies for the specific domain of biodiversity through the Darwin Core. This process, in turn, acts as the basis for the development of data standards for even more specific sub-disciplines (e.g., plant genetic resources) as well as a basis for collaboration with complementary related domains (e.g., metagenomics).
Implementation Guidelines
method↗mechanisms↗concepts↗concepts↗concepts↗concept_edgescontent_tagscontent_tags↗content_tags↗TDWG, as with other information standards bodies, has a history of developing data sharing standards that are bound to specific technologies, such as eXtensible Markup Language (XML). While Darwin Core is currently maintained in RDF, the enduring value of the standard lies in simple definitions of terms and their relationships to other terms, independent of technical implementation. As with Dublin Core, the idea is to promote use of the common terms in every appropriate context, and to leave the implementation details to specific applications. Data can be shared using Darwin Core in a variety of encoding schemes (Comma Separated Values, XML, JavaScript Object Notation, RDF, etc.). To aid in using Darwin Core in different contexts, there are documents with recommendations on how to share information as Darwin Core using various technologies.
mechanisms↗concepts↗concepts↗sensessensescontent_tagscontent_tags↗The Simple Darwin Core ( http://rs.tdwg.org/dwc/terms/simple/index.htm ) document explains the capacity to share records with properties that do not repeat, as simple text files or XML. There is also an XML Guide with reference XML schemas for highly structured data and a Text Guide explaining the construction of Darwin Core Archives (a combination of CSV files and a simple XML document describing the semantics of the data file columns and their relationships to each other). Darwin Core Archives can support structured data that conform to a star schema (a single core set of records in one or more files, with one-to-one or one-to-many relationships to records in other files). The Darwin Core Archive is becoming ever more popular as an easy means for data sharing, largely due to the release of supporting tools, in particular the next-generation data publishing system – the Integrated Publishing Toolkit ( http://www.gbif.org/informatics/infrastructure/publishing ) – an open source application developed by the Global Biodiversity Information Facility discussed in further detail below. Darwin Core Archives have been adopted by Pensoft® ( http://www.pensoft.net/journals/ ) as the preferred form for data appendices to taxonomic publications in MycoKeys, PhytoKeys, and ZooKeys.
Results
Development and Ratification as a Standard
content_tagsDarwin Core's development spans more than a decade, but rests on the earlier work of academic societies that addressed how to document or catalog specimens in natural history collections. Those societies put forward prescriptive guidelines about how to catalog specimens properly, first on paper and later in computer databases [27] – [29] . The purpose was to promote completeness in capture and consistency in representation or encoding. Actual data exchange and integration was anticipated as a future capability, but these guidelines preceded the Internet and World Wide Web.
concepts↗concepts↗concepts↗concepts↗unhoused_relationscontent_tags↗In the early 1990's, entity-relationship modeling had become accepted as a prerequisite for designing any database serving multiple users. A normalized database structure was the primary technique for enforcing data integrity. The Association of Systematic Collections (ASC) model [30] was the result of the first group effort to create a conceptual model for biological collections that accommodated the distinct taxonomic disciplines commonly found in natural history museums. The ASC model was an ontological description of the domain, but was determined at the time to be beyond the technical capabilities to implement [31] . Eventually, this model was then used as the point of departure for several collection management applications, including Specify ( http://specifysoftware.org/ ), Biota ( http://viceroy.eeb.uconn.edu/biota ), and Arctos ( http://arctos.database.museum/ ). The emphasis at that time was to develop best practice for data capture and management, not data exchange or integration.
concepts↗concepts↗The first successful tool to enable data integration in the biodiversity domain came to be known as the Species Analyst. A prototype based on the Z39.50 protocol [32] , which was popular in the Library Science community at that time, was deployed in a pilot project, the Z39.50 Biology Implementers Group (ZBIG, U.S. National Science Foundation NSF-DBI-9811443). An outcome of the first meeting of that project was a list of terms with definitions to be included in the profile. The name “Darwin Core” was coined by Allen Allison and adopted at that meeting. The Species Analyst, a project developed under the NSF-funded ZBIG project at the University of Kansas [33] , led to an international deployment of data servers [34] for ornithological (NSF-DBI-9808739) and ichthyological (NSF-DEB-9985737) [35] collections.
concepts↗concepts↗concept_edgesThe initial purpose of the Darwin Core was to facilitate the exchange of information about the geographic and temporal occurrence of organisms in the natural world and the physical existence of specimens in biological collections. In contrast to earlier guidelines, Darwin Core was not a prescription for how to manage collection information. Instead, it was designed to circumscribe a conceptual model for a research community aiming to create a loose federation of databases and advance its research capabilities through data integration. The barriers to publishing data in Darwin Core were purposefully kept as low as possible.
The informal Darwin Core terms developed for Species Analyst were further refined under the NSF-funded Mammal Networked Information System project (MaNIS, NSF-DBI-0108161, http://manisnet.org ) [36] and the Ornithological Information System project (ORNIS NSF-DBI-0345448, http://ornisnet.org ) [37] . Major goals of the MaNIS project were to employ HTTP as the transport protocol instead of the less widely used Z39.50, to create a message protocol to support web-based distributed queries (Distributed Generic Information Retrieval – DiGIR), and to enhance the set of terms to include information such as georeferences based on guidelines that address the capture of data quality metrics [38] . The goal under ORNIS was to make sure that the Darwin Core underwent the process of becoming a formal standard.
concepts↗concepts↗concepts↗claim_relationsconcept_edgesDarwin Core was developed in parallel with efforts in Europe to establish a comprehensive model for biological collections information — Access to Biological Collections Data (ABCD) [39] . The philosophies of the two approaches were distinct, even if they both had the goal of promoting sharing of biodiversity information. Darwin Core was designed to be minimal (only terms shared in common throughout natural history collections) and flat (no relational structure), while ABCD was highly structured and sought to capture the wide variety of biodiversity data and their relationships. Both groups defined their data models in XML schemas. ABCD was ratified as a standard by TDWG in 2005. Darwin Core departed from defining the standard in XML schema and followed the DCMI model, incorporating the experience of the previous decade to establish a set of terms in wide use in practice for data sharing.
content_tagscontent_tags↗Prior to ratification, Darwin Core had a history of versions [21] , each attempting to adapt to expanding community-defined needs. The earliest versions were limited to defining terms for biological specimens in collections. Continued development in sectors of the community produced versions with added capabilities targeting observations [40] and paleontology [41] . Standard Darwin Core reconciles the omissions from, incompatibilities between, and inconsistencies within previous versions and provides mappings to the out-dated terms as well as mappings to concepts in the ABCD Schema. In addition, terms were added to enable the transmission of taxonomic name and classification data sets. The result is a relatively simple and stable specification, which serves the needs of data publishers, data consumers, and application developers to work with primary biodiversity data.
content_tagscontent_tagsDarwin Core underwent a year of document development by the Darwin Core Task Group with support from the National Science Foundation and the Global Biodiversity Information Facility. The draft standard underwent review with public commentary before being ratified by the TDWG Executive Committee in October 2009.
Maintenance and Evolution
concepts↗concepts↗unhoused_relationsunhoused_relationsIn combination with openness and consensus building (key aspects of the TDWG constitution: http://www.tdwg.org/about-tdwg/constitution/ ), two of the guiding principles behind Darwin Core are flexibility and adaptability. The standard has to be flexible to accommodate a variety of ever evolving technical contexts in which it might be used (spreadsheet columns, relational database fields, XML schemas and documents, non-SQL data stores, and semantic web resources). The standard has to be adaptable to accommodate growth (new terms, additional meanings) and interoperability (connections to related information). To thrive, the standard must have a means to adapt to changing needs.
mechanisms↗concepts↗concepts↗content_tagscontent_tagsDarwin Core development is community driven and follows the process published in the Darwin Core Namespace Policy ( http://rs.tdwg.org/dwc/2009-09-23/terms/namespace/index.htm ). Open commentaries on issues related to Darwin Core are expressed through a public forum (at tdwg-content@lists.tdwg.org ) to which any subscriber may contribute. Discussions that result in consensus for change (new terms, new definitions, new relationships, changes in documentation) are submitted as change requests using templates requesting the appropriate information on the issue tracker of the Darwin Core Project site ( http://code.google.com/p/darwincore/wiki/SubmittingIssues ). Sometimes this process is reversed, with a submitted issue being copied to the discussion forum for elaboration and consensus before refining the issue as submitted. All changes undergo a 30-day public review, announced on the listserv. Changes are reviewed by TDWG's Technical Architecture Group (TAG: http://www.tdwg.org/activities/tag/ ), a set of volunteer members with broad interest and expertise in web-based interoperability. The TAG determines if the proposed changes are compatible with Darwin Core and that they do not reinvent existing standards. Changes that pass this review process are made as version changes to the affected documents, the latest of which always constitute the current standard.
Data Quality and Constraining Darwin Core
mechanisms↗concepts↗concepts↗concepts↗concepts↗unhoused_relationssensescontent_tags↗Data quality and fitness for use are primary concerns in the biodiversity community [42] , where information comes from heterogeneous sources spanning the globe over hundreds of years. Both data discovery and data quality assessment are hampered by this heterogeneity. Part of the solution depends on the use of common vocabularies, part on dictionaries of synonymous terms, and a great deal on applications that can facilitate discovery and assessment in place of or to aid in otherwise labor-intensive “cleanups”. For example, having a dictionary that equates “voucher” and “sample” with an accepted term “PreservedSpecimen” would allow applications to make this substitution automatically and allow users to discover relevant data using any of the synonyms regardless of how they were stored in the original data.
mechanisms↗limitationsunhoused_relationssensescontent_tagscontent_tagscontent_tags↗content_tags↗content_tags↗Darwin Core makes recommendations about constraints on data content, whether about data types, valid values, or controlled vocabularies. For example, decimalLatitude is recommended to be a floating-point number falling between 90 and −90, inclusive; countryCode is recommended to be a value from ISO 3166-1-alpha-2 (two-letter country codes). Though these recommendations are made in the standard, the philosophy is to relegate enforcement to applications where they make sense. For example, in a collaboration where the purpose is to automate data quality improvement on shared data, it is essential to be able to share the warts-and-all data that need to be investigated and improved.
Discussion
Frontiers
limitationsconcepts↗concepts↗claim_relationscontent_tagscontent_tags↗Though the Darwin Core is defined in an RDF document, integration of biodiversity data in the semantic web is in its early stages. One of the major challenges for Darwin Core in the semantic web context is the lack of a well-defined ontology - a formal definition of relationships between terms in a defined domain. An ontology would define the relationships between concepts such as biological entities, the events that document where and when they occurred, and the processes through which they are identified as being representative of a taxonomic concept. Without rigorous relationships between concepts and the properties that define them, connections between biodiversity data and related semantically rich information, such as literature and genomes, are difficult to traverse. This creates obstacles to cross-disciplinary semantic inquiry, such as in the Linked Data distributed data community ( http://linkeddata.org/ ). Current research is trying to address this gap (see TaxonConcept Knowledge Base, http://www.taxonconcept.org/ and BiSciCol, http://biscicol.blogspot.com/ ), active discussions on various aspects of the challenge take place regularly on the Darwin Core public forum ( http://lists.tdwg.org/mailman/listinfo/tdwg-content ), and an RDF task group has been established within TDWG “to adapt TDWG vocabularies for use as RDF classes and properties and to integrate those resources with other well-known vocabularies and ontologies outside TDWG for use in describing biodiversity resources.” [43]
Tools and Infrastructure for Publishing Darwin Core Data
concepts↗concepts↗unhoused_relationscontent_tagsA variety of tools has been developed to simplify the mobilization and sharing of biodiversity data using the Darwin Core. Many of these tools focus on the creation or validation of Darwin Core Archives ( http://code.google.com/p/darwincore/wiki/ToolsAndApplications#Tools ). The Global Biodiversity Information Facility (GBIF), an international organization promoting the free and open access to biodiversity data online, has invested heavily in the open and collaborative development of tools ( http://tools.gbif.org/ ) to make the creation and publication of Darwin Core Archives relatively simple.
mechanisms↗concepts↗concepts↗unhoused_relationsconcept_edgescontent_tags↗The Integrated Publishing Toolkit (IPT; http://www.gbif.org/informatics/infrastructure/publishing/ ) is an open-source software development project, led by GBIF, designed to address the challenges of sharing biodiversity data. By producing and providing easy access to Darwin Core Archives and resource metadata in Ecological Markup Language [44] , the IPT works in tandem with a Global Biodiversity Resources Discovery System (GBRDS), a data registry, to facilitate discovery and retrieval of shared data throughout the world. The IPT complements other tools that have been created to assist data users to explore, organize, and mobilize data sets. A range of spreadsheet and archive creators and validators has been developed by GBIF and others. These tools can be accessed via the GBIF Publishing Software web page ( http://www.gbif.org/informatics/standards-and-tools/publishing-data/publishing-software/ ).
mechanisms↗limitationsWhereas tools such as the IPT facilitate data mobilization using Darwin Core data, other tools build on these sources to integrate and index biodiversity data. These aggregators are thematic networks with either geographic (e.g., Atlas of Living Australia, http://www.ala.org.au/ ) or taxonomic focus (e.g., VertNet, http://vertnet.org ). Developing these systems to work sustainably and at large scales is an area of active research. For example, VertNet ( http://vertnet.org/ ), an aggregation of vertebrate specimen and observation data into a cloud-based data store, makes use of the Simple Darwin Core in comma separated value (.csv) files with header rows containing Darwin Core term names. These files are published to the data store where the records are indexed for high-performance querying.
Extensions
mechanisms↗limitationsconcepts↗unhoused_relationssensescontent_tagscontent_tags↗Because Darwin Core aims to cover the common ground in biodiversity, it inevitably lacks terms that are of interest to more specialized groups. A Darwin Core Extension consists of additional terms describing a complementary, related domain, or guidance on the use of Darwin Core within a specific sub-domain of biodiversity. Over the last decade, Darwin Core has evolved by means of extensions, some of which have been incorporated in the standard. For example, the terms of a paleontology extension related to an earlier, pre-standard version of Darwin Core became the terms of the current GeologicalContext class. Similarly, terms originating from an early version of the Darwin Core created for the Ocean Biogeographic Information System (OBIS; http://www.iobis.org/ ) have also been added to Darwin Core. Going forward, specific projects or disciplines may find it convenient to extend the scope of Darwin Core outside the existing namespace and governance process for proof-of-concept research. Once the understanding of the new terms has been tested and proven of utility in a broader context, incorporation into the standard can be accomplished through community consensus.
Integration of Darwin Core with New Research Communities
claim_relationsDarwin Core continues to be integrated into new research communities. For example, the Nordic Genetic Resource Center (NordGen; http://www.nordgen.org ) and Bioversity International (formerly IPGRI) ( http://www.bioversityinternational.org ) have sought to take advantage of Darwin Core on behalf of the European plant genetic resources and genebank community and, at the same time, share rich discipline-specific genetic resource information. A careful review was made of Darwin Core and a set of additional terms that did not overlap or conflict with existing Darwin Core terms was proposed to meet the community's needs. The new terms, modeled directly from FAO/IPGRI Multi-Crop Passport Descriptors [45] (2001) and the proposed EPGRIS3 trait data standard for characterization and evaluation data [46] , were expressed and published openly in an XML schema for germplasm data (DwC-germplasm, http://code.google.com/p/darwincore-germplasm/ ) [47] , resulting in the first successfully deployed extension to the Darwin Core Standard.
The success of DwC-germplasm has encouraged other communities to supplement or work in parallel with Darwin Core to meet specific needs. For example, the Apiary Project ( http://www.apiaryproject.org/ ) extended the Darwin Core to capture basic specimen information along with detailed annotation data (e.g., annotatedBy, dateAnnotated) found on herbarium sheets. Other communities are focusing on providing guidelines on how to use Darwin Core within a discipline without the need for extensions. The Apple Core Initiative ( http://code.google.com/p/applecore/wiki/Introduction ), organized by Canadensys, ( http://www.canadensys.net/ ), is aimed at providing guidance on best practices for the content of Darwin Core terms for vascular plant specimens.
concepts↗A set of taxonomic extensions collectively known as the “GNA Profile” (named for the Global Names Architecture) [48] – [49] have been designed by GBIF with input from Catalogue of Life ( http://www.catalogueoflife.org/ ), Encyclopedia of Life ( http://eol.org/ ), nomenclators, and other taxonomic initiatives. These extensions ( http://rs.gbif.org/extension/gbif/1.0/ ), together with the taxonomic terms of Darwin Core, allow sharing of rich taxonomic data often found in species checklists. The extensions are designed to be used in a one-to-many relationship with core taxon records, allowing the sharing of structured data such as vernacular names, species range distributions, textual descriptions, type species and specimens, image data, and bibliographies.
concepts↗An effort is underway within TDWG to create a standard for biodiversity multimedia resources and collections, called the Audubon Core [50] . The proposal introduces vocabularies covering the management and content of biodiversity-related media and their taxonomic, geographic, and temporal scope. Audubon Core adopts by inclusion a number of terms from Darwin Core, which can reduce the burden on existing media publishers who may have already used Darwin Core terms for describing the media content.
concepts↗concept_edgesIn collaboration with the Genomic Standards Consortium (GSC; http://gensc.org/ ) [51] , Darwin Core is now being extended to cover DNA-level observations (genomes, metagenomes, and gene marker sequences). The GSC, a standards body similar in scope to Biodiversity Information Standards (TDWG), is working to “standardize the description of genomic data and promote the exchange and integration of genomic data. [52] .” Advances in technology have made sequence-based diversity assessments increasingly routine in biodiversity research. The GSC has developed the MIxS (Minimum Information about any (x) Sequence) standard containing checklists for describing genomes, metagenomes, and marker gene studies. Conceptually this approach is similar to Darwin Core in that it defines terms for the description of data, but differs in that it requires the reporting a certain minimum set of descriptors such as environmental and geographic origin and details about sample and sequencing processing in addition to any kind of genomic sequence.
mechanisms↗unhoused_relationsclaim_relationscontent_tagsCurrently, Darwin Core and GSC developers are collaborating (supported by NSF-RCN4GSC) to harmonize Darwin Core and MIxS to aid the growing field of sequence-based diversity research. Darwin Core and GSC developers have concluded that the standards are conceptually similar and that the distinct sets of terms are complementary. This allows the development of a bi-directional (see Figure 2 ) solution, where in the future the GSC will be able to incorporate terms from Darwin Core and add GSC-specific reporting requirements, while Darwin Core will be able to offer a genomics extension using the results of this activity.
Scope and Scale of Darwin Core for Biodiversity Science
concepts↗concepts↗concepts↗content_tagsThe creation of a standard format for biodiversity data, the development of aggregation tools, and the increasing use of Darwin Core Archives have helped to overcome the challenge of limited availability of data to answer questions about biodiversity. As more data become digitized and discoverable, biocollections can become a window into broader analyses of ecological, climate, niche, environmental, and biological research questions and critical issues.
mechanisms↗concepts↗claim_relationscontent_tagsThough predated by examples of the effective use of Darwin Core for distribution modeling, influence of natural area preservation, and estimates of climate change impact [53] , the utility of data shared using Darwin Core is illustrated by two recent examples. First, the University of California, Berkeley, and the Wildlife Conservation Society have collaborated to create Réseau de la Biodiversité de Madagascar (REBIOMA, http://www.rebioma.net/ ).The effort seeks to make biodiversity data about Madagascar available via a single web-based resource. Primary data on biodiversity in Madagascar come from researchers and institutions all over the world. REBIOMA works with each collection to standardize the data using the Darwin Core, to mobilize and aggregate the data, and to vet the data for quality, completeness, and fitness for use. Data passing automated quality checks and review by a board of taxonomic experts are analyzed in combination with environmental data to produce maps showing models of where species might occur. The success of this project has made it possible for researchers, policy makers, government officials, and conservationists to capture a wealth of data to address issues of Malagasy biodiversity. The simplicity and flexibility of Darwin Core has made it possible for REBIOMA to provide immediate access to high-quality data and tools for monitoring and assessing conservation efforts.
mechanisms↗concepts↗A second example of innovative use of Darwin Core data is the Map of Life Project ( http://www.mappinglife.org/ ), and sister projects such as LifeMapper ( http://www.lifemapper.org/ ) [54] , which aggregate and mobilize sources of species distribution information and provide tools to visualize and analyses those data. In Map of Life, species occurrence data points formatted as Darwin Core are queried and brought into the application with related data sources such as range maps, assemblage checklists, and habitat preference data. Integration of these data types and modeling will lead to summary products describing species distributions and provide the basis for distribution change assessments in the face of human-induced global changes [55] . The Map of Life will be a knowledge base of hundreds of thousands of high-resolution species distribution maps covering a wide range of taxa and geographic locations.
Conclusions
content_tagsThe demand for Darwin Core data is increasing. The corpus of information spanning three centuries of biodiversity exploration is being digitized at an increasing rate. Major efforts such as the new US National Science Foundation program Advancing Digitization of Biological Collections ( http://nsf.gov/funding/pgm_summ.jsp?pims_id=503559&org=DBI&from=home ) and the Atlas of Living Australia ( http://www.ala.org.au ) are two recent examples. A flood of qualitatively new global biodiversity data is also being generated through the application of high-throughput gene sequencing of environmental samples.
limitationsThe President's Council of Advisors on Science and Technology (PCAST) report on sustaining environmental capital noted recently that the challenge is not only one of the volume of data, but also its heterogeneity, as traditional biotic surveying practices blend with new approaches, such as remote sensing [56] or metagenomics [57] . A key passage in that PCAST report captures the challenge perfectly: “temporal, spatial, and methodological heterogeneity leads to a depth and richness in biodiversity and ecosystems data not found in other fields. It also makes dataset interoperability a problem that is at the same time particularly challenging and highly important to solve [58] .” Darwin Core fills an essential role in describing some of these data in a standard format based on community input and demonstrated utility.
concepts↗concepts↗unhoused_relationssensesconcept_edgescontent_tagscontent_tags↗Darwin Core is a living standard. Although its roots were planted in the vertebrate natural history collections community, Darwin Core continues to grow to serve the needs of biodiversity research. This growth, over the relatively short period of a decade, speaks both to the need for such a standard and to the efforts of its champions to increase its utility through a community development process in order to meet increasing demand. Darwin Core greatly increases the value and re-use of freely available and accessible biodiversity data so that they can be effectively mobilized, integrated, and incorporated into other “grand challenge” scientific endeavors.
Relations on this page carry a quotation for the claim. Where a relation was separately evidenced — and so tested against the vocabulary for its type — the row says so; 11 of 11 relations here carry that mark. The rest are the tagger’s reading of the sentence quoted beside them.
This record holds no controls. A layer is empty when the tagger recorded nothing in it — which is not the same as the paper having nothing to record.
| facet | tag | field | conf. | whose words |
|---|---|---|---|---|
| object_of_study | Darwin Core as a community-developed standard for publishing, sharing, and integrating biodiversity data | object_of_study | the paper's words | |
| research_question | how Darwin Core defines a common semantic language, is implemented and governed, and evolves across biodiversity research communities | research_question | the paper's words | |
| contribution | an account of Darwin Core's semantic structure, history, implementation patterns, governance, extensions, and knowledge-producing infrastructure | contribution | the paper's words | |
| claim_type | method | claim_type | the paper's words | |
| phenomenon | interoperability and integration of heterogeneous biodiversity information | phenomenon | the paper's words | |
| method | practice-report also in: practice-report | method | the paper's words | |
| mechanisms | A standardized view and definitions of common terms make heterogeneous biodiversity sources interoperable. also in: semantic standardization | mechanisms[0] | 0.98 | the tagger's words |
| mechanisms | A common language permits biodiversity data sharing while reusing metadata standards from other domains. also in: common-language sharing | mechanisms[1] | 0.98 | the tagger's words |
| mechanisms | Clearly defined semantics let people and machines interpret records and determine appropriate data uses. also in: defined-term interpretation | mechanisms[2] | 0.99 | the tagger's words |
| mechanisms | Stable term definitions can be reused across CSV, XML, JSON, RDF, and other technical contexts. also in: implementation independence | mechanisms[3] | 0.98 | the tagger's words |
| mechanisms | A small XML descriptor connects CSV columns and record relationships in a Darwin Core Archive. also in: archive semantics | mechanisms[4] | 0.98 | the tagger's words |
| mechanisms | Public discussion, change requests, review, and versioning adapt the standard without abandoning compatibility. also in: open consensus governance | mechanisms[5] | 0.98 | the tagger's words |
| mechanisms | A dictionary can map voucher and sample to PreservedSpecimen so applications substitute terms and improve discovery. also in: synonym normalization | mechanisms[6] | 0.98 | the tagger's words |
| mechanisms | The standard recommends constraints while applications enforce them only where the collaboration requires. also in: application-level validation | mechanisms[7] | 0.98 | the tagger's words |
| mechanisms | The IPT produces archives and metadata while a registry enables global discovery and retrieval. also in: publishing and registry coupling | mechanisms[8] | 0.98 | the tagger's words |
| mechanisms | Thematic networks ingest Darwin Core files into stores indexed for high-performance querying. also in: aggregation and indexing | mechanisms[9] | 0.95 | the tagger's words |
| mechanisms | Specialized terms are tested outside the core namespace and incorporated after broader utility and consensus are established. also in: extension lifecycle | mechanisms[10] | 0.98 | the tagger's words |
| mechanisms | Complementary Darwin Core and MIxS terms support reciprocal reuse plus domain-specific reporting requirements. | mechanisms[11] | 0.98 | the tagger's words |
| mechanisms | REBIOMA standardizes, mobilizes, aggregates, vets, and models distributed occurrence data. also in: standardized conservation workflow | mechanisms[12] | 0.97 | the tagger's words |
| mechanisms | Map of Life combines Darwin Core occurrence points with ranges, checklists, habitat data, and models to produce distribution products. also in: knowledge-base integration | mechanisms[13] | 0.95 | the tagger's words |
| limitations | Existing biodiversity repositories tend to remain isolated without coordinated publishing standards and communication protocols. | limitations[0] | 0.99 | the tagger's words |
| limitations | Broad-scale biodiversity analysis is impeded by data that are not accessible at the necessary spatial and temporal scales. | limitations[1] | 0.98 | the tagger's words |
| limitations | Locally evolved curation practices vary by discipline and institution and historically lacked a data-sharing culture. | limitations[2] | 0.98 | the tagger's words |
| limitations | Simple Darwin Core cannot easily represent repeating properties and relationships that need complex structures. | limitations[3] | 0.98 | the tagger's words |
| limitations | Darwin Core's common-ground scope inevitably omits terms needed by specialized research groups. | limitations[4] | 0.99 | the tagger's words |
| limitations | Semantic-web integration was early-stage and hindered by the absence of a formal ontology relating Darwin Core concepts. | limitations[5] | 0.99 | the tagger's words |
| limitations | Sustainable operation of large-scale biodiversity aggregators remained an active research problem. | limitations[6] | 0.95 | the tagger's words |
| limitations | Recommended constraints are not enforced by the standard itself, leaving their application context-dependent. | limitations[7] | 0.98 | the tagger's words |
| limitations | Growing biodiversity data combine large volume with temporal, spatial, and methodological heterogeneity. | limitations[8] | 0.98 | the tagger's words |
| concepts | Biodiversity data also in: Biodiversity data | concepts[0] | 0.99 | the paper's words |
| concepts | standardized view also in: standardized view | concepts[1] | 0.98 | the paper's words |
| concepts | interoperability also in: interoperability | concepts[2] | 0.99 | the paper's words |
| concepts | common terms also in: common terms | concepts[3] | 0.98 | the paper's words |
| concepts | Darwin Core also in: Darwin Core | concepts[4] | 0.99 | the paper's words |
| concepts | data standard also in: data standard | concepts[5] | 0.98 | the paper's words |
| concepts | biodiversity information also in: biodiversity information | concepts[6] | 0.98 | the paper's words |
| concepts | Simple Darwin Core also in: Simple Darwin Core | concepts[7] | 0.99 | the paper's words |
| concepts | relational Darwin Core also in: relational Darwin Core | concepts[8] | 0.95 | the paper's words |
| concepts | common language also in: common language | concepts[9] | 0.99 | the paper's words |
| concepts | clearly defined semantics also in: clearly defined semantics | concepts[10] | 0.99 | the paper's words |
| concepts | people also in: people | concepts[11] | 0.98 | the paper's words |
| concepts | machines also in: machines | concepts[12] | 0.98 | the paper's words |
| concepts | nine categories also in: nine categories | concepts[13] | 0.99 | the paper's words |
| concepts | seven categories of terms also in: seven categories of terms | concepts[14] | 0.99 | the paper's words |
| concepts | Dublin Core also in: Dublin Core | concepts[15] | 0.99 | the paper's words |
| concepts | authoritative form also in: authoritative form | concepts[16] | 0.98 | the paper's words |
| concepts | Resource Description Framework also in: Resource Description Framework | concepts[17] | 0.99 | the paper's words |
| concepts | technical implementation also in: technical implementation | concepts[18] | 0.98 | the paper's words |
| concepts | encoding schemes also in: encoding schemes | concepts[19] | 0.98 | the paper's words |
| concepts | Darwin Core Archives also in: Darwin Core Archives | concepts[20] | 0.99 | the paper's words |
| concepts | star schema also in: star schema | concepts[21] | 0.98 | the paper's words |
| concepts | Integrated Publishing Toolkit also in: Integrated Publishing Toolkit | concepts[22] | 0.99 | the paper's words |
| concepts | entity-relationship modeling also in: entity-relationship modeling | concepts[23] | 0.98 | the paper's words |
| concepts | normalized database structure also in: normalized database structure | concepts[24] | 0.98 | the paper's words |
| concepts | ASC model also in: ASC model | concepts[25] | 0.98 | the paper's words |
| concepts | ontological description also in: ontological description | concepts[26] | 0.95 | the paper's words |
| concepts | Species Analyst also in: Species Analyst | concepts[27] | 0.99 | the paper's words |
| concepts | Z39.50 protocol also in: Z39.50 protocol | concepts[28] | 0.98 | the paper's words |
| concepts | loose federation of databases also in: loose federation of databases | concepts[29] | 0.98 | the paper's words |
| concepts | ABCD also in: ABCD | concepts[30] | 0.99 | the paper's words |
| concepts | minimal also in: minimal | concepts[31] | 0.98 | the paper's words |
| concepts | flat also in: flat | concepts[32] | 0.98 | the paper's words |
| concepts | flexibility also in: flexibility | concepts[33] | 0.98 | the paper's words |
| concepts | adaptability also in: adaptability | concepts[34] | 0.98 | the paper's words |
| concepts | community driven also in: community driven | concepts[35] | 0.98 | the paper's words |
| concepts | consensus also in: consensus | concepts[36] | 0.98 | the paper's words |
| concepts | data quality also in: data quality | concepts[37] | 0.99 | the paper's words |
| concepts | fitness for use also in: fitness for use | concepts[38] | 0.99 | the paper's words |
| concepts | common vocabularies also in: common vocabularies | concepts[39] | 0.98 | the paper's words |
| concepts | dictionaries of synonymous terms also in: dictionaries of synonymous terms | concepts[40] | 0.98 | the paper's words |
| concepts | semantic web also in: semantic web | concepts[41] | 0.99 | the paper's words |
| concepts | ontology also in: ontology | concepts[42] | 0.99 | the paper's words |
| concepts | Darwin Core Extension also in: Darwin Core Extension | concepts[43] | 0.99 | the paper's words |
| concepts | GNA Profile also in: GNA Profile | concepts[44] | 0.98 | the paper's words |
| concepts | Audubon Core also in: Audubon Core | concepts[45] | 0.98 | the paper's words |
| concepts | MIxS also in: MIxS | concepts[46] | 0.99 | the paper's words |
| concepts | aggregation tools also in: aggregation tools | concepts[47] | 0.98 | the paper's words |
| concepts | REBIOMA also in: REBIOMA | concepts[48] | 0.99 | the paper's words |
| concepts | Map of Life also in: Map of Life | concepts[49] | 0.99 | the paper's words |
| concepts | living standard also in: living standard | concepts[50] | 0.98 | the paper's words |
| concepts | lack of a coordinated publishing and integration system | concepts[51] | 0.98 | the paper's words |
| concepts | data repositories also in: data repositories | concepts[52] | 0.98 | the paper's words |
| concepts | Heterogeneity in meaning and content of terms | concepts[53] | 0.98 | the paper's words |
| concepts | obstacles in every aspect of data integration and use | concepts[54] | 0.95 | the paper's words |
| concepts | simple definitions of terms also in: simple definitions of terms | concepts[55] | 0.98 | the paper's words |
| concepts | creation and publication of Darwin Core Archives relatively simple | concepts[56] | 0.95 | the paper's words |
| concepts | limited availability of data also in: limited availability of data | concepts[57] | 0.98 | the paper's words |
| concepts | value and re-use also in: value and re-use | concepts[58] | 0.95 | the paper's words |
| concepts | standard for sharing data about biodiversity | concepts[59] | 0.99 | the paper's words |
| concepts | set of terms also in: set of terms | concepts[60] | 0.99 | the paper's words |
| concepts | standard for encoding the semantic structure of web-based resources | concepts[61] | 0.99 | the paper's words |
| concepts | open-source software development project | concepts[62] | 0.99 | the paper's words |
| concepts | earlier guidelines also in: earlier guidelines | concepts[63] | 0.98 | the paper's words |
| concepts | A variety of tools also in: A variety of tools | concepts[64] | 0.98 | the paper's words |
| concepts | standard format for biodiversity data | concepts[65] | 0.98 | the paper's words |
| unhoused_relations | Darwin Core → metadata standards from other domains Darwin Core is complementary to and reuses metadata standards from other domains. | unhoused_relations[0] | 0.98 | the tagger's words |
| unhoused_relations | Darwin Core → natural history collections Darwin Core has its historical roots in the natural-history collections community. | unhoused_relations[1] | 0.99 | the tagger's words |
| unhoused_relations | Darwin Core → technical contexts The standard must remain flexible across evolving technical contexts. | unhoused_relations[2] | 0.98 | the tagger's words |
| unhoused_relations | Darwin Core → changing needs The standard must adapt to changing needs through new terms, meanings, and connections. | unhoused_relations[3] | 0.98 | the tagger's words |
| unhoused_relations | common vocabularies and synonym dictionaries → data discovery and quality assessment Shared vocabularies and synonym mappings are parts of the proposed solution to heterogeneous-data discovery and quality problems. | unhoused_relations[4] | 0.97 | the tagger's words |
| unhoused_relations | Darwin Core constraints → applications The standard recommends constraints but delegates enforcement to applications. | unhoused_relations[5] | 0.99 | the tagger's words |
| unhoused_relations | Integrated Publishing Toolkit → Global Biodiversity Resources Discovery System The publishing toolkit works in tandem with the registry to support discovery and retrieval. | unhoused_relations[6] | 0.98 | the tagger's words |
| unhoused_relations | Darwin Core Extension → specialized groups Extensions supply terms and guidance missing from the common-ground core for specialized groups. | unhoused_relations[7] | 0.98 | the tagger's words |
| unhoused_relations | Darwin Core → MIxS The standards are conceptually similar and have complementary term sets. | unhoused_relations[8] | 0.99 | the tagger's words |
| unhoused_relations | Darwin Core records → new knowledge products Integrated records support new products documenting distributions and environmental change. | unhoused_relations[9] | 0.97 | the tagger's words |
| unhoused_relations | Darwin Core → grand challenge scientific endeavors Mobilized and integrated Darwin Core data can be incorporated into broader scientific programs. | unhoused_relations[10] | 0.97 | the tagger's words |
| unhoused_relations | ASC model → ontological description The ASC model was an ontological description of the biological-collections domain. | unhoused_relations[11] | 0.98 | the tagger's words |
| unhoused_relations | lack of a coordinated publishing and integration system → data repositories Repositories tend to be isolated when coordinated systems and standards are absent. | unhoused_relations[12] | 0.95 | the tagger's words |
| unhoused_relations | Heterogeneity in meaning and content of terms → obstacles in every aspect of data integration and use Semantic heterogeneity creates obstacles to discovery, comparison, quality assessment, and integration. | unhoused_relations[13] | 0.98 | the tagger's words |
| unhoused_relations | clearly defined semantics → human and machine interpretation Defined semantics make human understanding and machine interpretation possible. | unhoused_relations[14] | 0.97 | the tagger's words |
| unhoused_relations | A variety of tools → creation and publication of Darwin Core Archives relatively simple GBIF-supported tools are intended to make archive creation and publication simpler. | unhoused_relations[15] | 0.96 | the tagger's words |
| senses | Darwin Core - sharing standard: common terms for biodiversity occurrence and environmental-association data | senses[0] | 0.99 | the tagger's words |
| senses | Darwin Core - semantic resource: a set of terms with human- and machine-interpretable meanings | senses[1] | 0.99 | the tagger's words |
| senses | Darwin Core - living standard: a community process that adapts terms and relationships to new needs | senses[2] | 0.98 | the tagger's words |
| senses | Simple Darwin Core - flat-record sense: nonrepeating properties in text or XML | senses[3] | 0.98 | the tagger's words |
| senses | Darwin Core Archive - star-schema sense: core records plus one-to-one or one-to-many extension records | senses[4] | 0.98 | the tagger's words |
| senses | constraint - recommendation sense: guidance whose enforcement belongs to applications | senses[5] | 0.98 | the tagger's words |
| senses | extension - specialist sense: complementary terms or use guidance for a biodiversity sub-domain | senses[6] | 0.99 | the tagger's words |
| senses | data quality - fitness-for-use sense: contextual suitability assessed across heterogeneous sources | senses[7] | 0.98 | the tagger's words |
| claim_relations | builds-on → Dublin Core Metadata Initiative note: Darwin Core inherits mission, operating principles, terms, and governance ideas from Dublin Core. | claim_relations[0] | 0.98 | the tagger's words |
| claim_relations | contrasts-with → Access to Biological Collections Data note: The paper explicitly contrasts Darwin Core's minimal flat approach with ABCD's highly structured model. | claim_relations[1] | 0.98 | the tagger's words |
| claim_relations | supports → biodiversity-data interoperability note: Common definitions and a standardized view are presented as the basis for integration. | claim_relations[2] | 0.98 | the tagger's words |
| claim_relations | extends → Darwin Core beyond natural-history collections note: A deployed germplasm extension carries the standard into genetic-resource research. | claim_relations[3] | 0.98 | the tagger's words |
| claim_relations | qualifies → semantic-web use of Darwin Core note: The missing formal ontology limits traversable links to semantically rich resources. | claim_relations[4] | 0.99 | the tagger's words |
| claim_relations | demonstrates → Darwin Core's research and conservation utility note: The REBIOMA case shows standardization leading to quality-controlled occurrence models and conservation access. | claim_relations[5] | 0.97 | the tagger's words |
| claim_relations | complements → MIxS genomic-data standard note: The communities concluded that the standards have distinct, complementary term sets. | claim_relations[6] | 0.98 | the tagger's words |
| concept_edges | Darwin Core —is-a→ standard for sharing data about biodiversity the relation itself is separately evidenced · strength of the relation: 1 · note: Categorical class relation. · the relation stated: Darwin Core is explicitly defined as a standard for sharing biodiversity data. | concept_edges[0] | 0.99 | the tagger's words |
| concept_edges | Darwin Core —is-a→ set of terms the relation itself is separately evidenced · strength of the relation: 1 · note: Categorical class relation. · the relation stated: Darwin Core is explicitly defined as a set of semantically defined terms. also in: Darwin Core · set of terms | concept_edges[1] | 0.99 | the tagger's words |
| concept_edges | Resource Description Framework —is-a→ standard for encoding the semantic structure of web-based resources the relation itself is separately evidenced · strength of the relation: 1 · note: Categorical class relation. · the relation stated: RDF is explicitly described as a standard for encoding semantic structure. | concept_edges[2] | 0.99 | the tagger's words |
| concept_edges | Integrated Publishing Toolkit —is-a→ open-source software development project the relation itself is separately evidenced · strength of the relation: 1 · note: Categorical class relation. · the relation stated: The IPT is explicitly described as an open-source software development project. | concept_edges[3] | 0.99 | the tagger's words |
| concept_edges | seven categories of terms —part-of→ Simple Darwin Core the relation itself is separately evidenced · strength of the relation: 1 · note: Categorical containment relation. · the relation stated: Simple Darwin Core is explicitly comprised of these seven categories. also in: seven categories of terms · Simple Darwin Core | concept_edges[4] | 0.99 | the tagger's words |
| concept_edges | Darwin Core —distinct-from→ Dublin Core the relation itself is separately evidenced · strength of the relation: 0.95 · note: Flat distinction statement. · the relation stated: Their scope and governance are explicitly distinct despite shared ancestry.
Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but the span says the SCOPE and governance are distinct while stressing shared ancestry; distinct-from is loose. also in: Darwin Core · Dublin Core | concept_edges[5] | 0.99 | the tagger's words |
| concept_edges | Darwin Core —contrasted-with→ earlier guidelines the relation itself is separately evidenced · strength of the relation: 0.95 · note: Flat explicit contrast. · the relation stated: The paper explicitly contrasts Darwin Core's integration aim with earlier management prescriptions. also in: Darwin Core · earlier guidelines | concept_edges[6] | 0.99 | the tagger's words |
| concept_edges | Darwin Core —contrasted-with→ ABCD the relation itself is separately evidenced · strength of the relation: 0.95 · note: Flat explicit contrast. · the relation stated: The paper contrasts minimal flat Darwin Core with highly structured ABCD. also in: Darwin Core · ABCD | concept_edges[7] | 0.99 | the tagger's words |
| concept_edges | MIxS —distinct-from→ Darwin Core the relation itself is separately evidenced · strength of the relation: 0.95 · note: Flat difference statement. · the relation stated: MIxS explicitly differs by requiring a minimum descriptor set. also in: MIxS · Darwin Core | concept_edges[8] | 0.98 | the tagger's words |
| concept_edges | simple definitions of terms —distinct-from→ technical implementation the relation itself is separately evidenced · strength of the relation: 0.95 · note: Flat independence statement. · the relation stated: Enduring semantic definitions are stated to be independent of implementation technology.
Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but the span says the value lies in definitions INDEPENDENT of implementation; distinct-from is loose. | concept_edges[9] | 0.98 | the tagger's words |
| concept_edges | Darwin Core —causes→ value and re-use the relation itself is separately evidenced · strength of the relation: 0.9 · note: Flat causal assertion. · the relation stated: The standard is stated to greatly increase data value and reuse. also in: Darwin Core · value and re-use | concept_edges[11] | 0.97 | the tagger's words |
| content_tags | Semantic heterogeneity and isolated repositories obstruct biodiversity-data discovery, comparison, quality assessment, and integration. | content_tags.findings[0] | 0.98 | the tagger's words |
| content_tags | Darwin Core was widely deployed, with GBIF indexing about 300 million formatted records from more than 340 organizations in 43 countries. | content_tags.findings[1] | 0.99 | the tagger's words |
| content_tags | Darwin Core organizes its terms into nine categories, six covering broad biodiversity-domain aspects and three covering relations, measurements, and record information. | content_tags.findings[2] | 0.98 | the tagger's words |
| content_tags | Simple Darwin Core uses seven categories representable in one flat file, while two further categories require more complex structures. | content_tags.findings[3] | 0.98 | the tagger's words |
| content_tags | The enduring value of the standard lies in term definitions and relationships that remain independent of implementation technology. | content_tags.findings[4] | 0.98 | the tagger's words |
| content_tags | Darwin Core Archives gained adoption as an easy sharing format supported by publishing tools and taxonomic journals. | content_tags.findings[5] | 0.95 | the tagger's words |
| content_tags | Standard Darwin Core reconciled omissions and incompatibilities across earlier versions and maps obsolete terms and ABCD concepts. | content_tags.findings[6] | 0.98 | the tagger's words |
| content_tags | The draft standard received public review and was ratified by the TDWG Executive Committee in October 2009. | content_tags.findings[7] | 0.99 | the tagger's words |
| content_tags | Darwin Core changes proceed through public discussion, consensus, formal requests, technical review, and versioned documents. | content_tags.findings[8] | 0.98 | the tagger's words |
| content_tags | The standard recommends content constraints but deliberately leaves enforcement to applications where appropriate. | content_tags.findings[9] | 0.98 | the tagger's words |
| content_tags | Semantic-web integration remained early-stage because Darwin Core lacked a well-defined ontology connecting domain concepts. | content_tags.findings[10] | 0.98 | the tagger's words |
| content_tags | GBIF tools simplify archive creation and publication, while aggregators integrate and index Darwin Core data for discovery and querying. | content_tags.findings[11] | 0.95 | the tagger's words |
| content_tags | Extensions let specialized communities add terms and can later enter the standard after testing and community consensus. | content_tags.findings[12] | 0.98 | the tagger's words |
| content_tags | Darwin Core and MIxS were judged conceptually similar and their distinct term sets complementary, enabling bidirectional harmonization. | content_tags.findings[13] | 0.98 | the tagger's words |
| content_tags | Standard formats, aggregation tools, and Darwin Core Archives helped overcome limited data availability for biodiversity questions. | content_tags.findings[14] | 0.95 | the tagger's words |
| content_tags | The REBIOMA case used Darwin Core standardization, aggregation, and quality review to provide conservation data and distribution models for Madagascar. | content_tags.findings[15] | 0.95 | the tagger's words |
| content_tags | The authors characterize Darwin Core as a living standard that increases the value and reuse of accessible biodiversity data. | content_tags.findings[16] | 0.98 | the tagger's words |
| content_tags | a standard for sharing biodiversity occurrence data and their environmental associations also in: Darwin Core | content_tags.definitions[0] | 0.99 | the tagger's words |
| content_tags | a seven-category subset representable as one file with one row per record and one column per term also in: Simple Darwin Core | content_tags.definitions[1] | 0.99 | the tagger's words |
| content_tags | CSV data files plus a simple XML document describing column semantics and relationships also in: Darwin Core Archives | content_tags.definitions[2] | 0.98 | the tagger's words |
| content_tags | the primary database-design technique described for enforcing data integrity also in: normalized database structure | content_tags.definitions[3] | 0.95 | the tagger's words |
| content_tags | a formal definition of relationships between terms in a defined domain also in: ontology | content_tags.definitions[4] | 0.99 | the tagger's words |
| content_tags | an open-source GBIF project for publishing Darwin Core Archives and metadata also in: Integrated Publishing Toolkit | content_tags.definitions[5] | 0.99 | the tagger's words |
| content_tags | additional terms for a related domain or guidance for using Darwin Core in a biodiversity sub-domain also in: Darwin Core Extension | content_tags.definitions[6] | 0.99 | the tagger's words |
| content_tags | a standard that continues to grow through community development as research needs change also in: living standard | content_tags.definitions[7] | 0.95 | the tagger's words |
| content_tags | approximately 300 million Darwin Core-formatted records — records indexed by GBIF at the time described | content_tags.quantities[0] | 0.99 | the tagger's words |
| content_tags | more than 340 organizations — organizations publishing the indexed Darwin Core records | content_tags.quantities[1] | 0.99 | the tagger's words |
| content_tags | 43 countries — country coverage of the indexed records | content_tags.quantities[2] | 0.99 | the tagger's words |
| content_tags | nine categories — total categories organizing Darwin Core terms | content_tags.quantities[3] | 0.99 | the tagger's words |
| content_tags | seven categories of terms — categories comprising Simple Darwin Core | content_tags.quantities[4] | 0.99 | the tagger's words |
| content_tags | Two additional categories — categories requiring more complex data structures | content_tags.quantities[5] | 0.99 | the tagger's words |
| content_tags | one row per record — flat-file record cardinality in Simple Darwin Core | content_tags.quantities[6] | 0.99 | the tagger's words |
| content_tags | one column per term — flat-file field cardinality in Simple Darwin Core | content_tags.quantities[7] | 0.99 | the tagger's words |
| content_tags | October 2009 — month of Darwin Core ratification | content_tags.quantities[8] | 0.99 | the tagger's words |
| content_tags | more than a decade — development span described for Darwin Core | content_tags.quantities[9] | 0.99 | the tagger's words |
| content_tags | 30-day public review — public review period for standard changes | content_tags.quantities[10] | 0.99 | the tagger's words |
| content_tags | between 90 and −90, inclusive — recommended value range for decimalLatitude | content_tags.quantities[11] | 0.99 | the tagger's words |
| content_tags | three centuries — historical span of biodiversity information being digitized | content_tags.quantities[12] | 0.99 | the tagger's words |
| content_tags | semantics also in: semantics | content_tags.variables[0] | 0.99 | the tagger's words |
| content_tags | categories also in: categories | content_tags.variables[1] | 0.98 | the tagger's words |
| content_tags | technical implementation also in: technical implementation | content_tags.variables[2] | 0.98 | the tagger's words |
| content_tags | encoding schemes also in: encoding schemes | content_tags.variables[3] | 0.98 | the tagger's words |
| content_tags | community-defined needs also in: community-defined needs | content_tags.variables[4] | 0.95 | the tagger's words |
| content_tags | data types also in: data types | content_tags.variables[5] | 0.98 | the tagger's words |
| content_tags | valid values also in: valid values | content_tags.variables[6] | 0.98 | the tagger's words |
| content_tags | controlled vocabularies also in: controlled vocabularies | content_tags.variables[7] | 0.98 | the tagger's words |
| content_tags | fitness for use also in: fitness for use | content_tags.variables[8] | 0.98 | the tagger's words |
Tags that could not be placed in the text:
What was deliberately not tagged, and why, is recorded per paper by the tagger. Where a paper has no such record, this page says so rather than implying that nothing was declined.