This, 2009, is the year for putting government data online. Both US and UK governments made public commitments toward open data.—Tim Berners-Lee
• In the open stage, government agencies play a key role in putting OGD datasets online in reusable formats and maintaining central OGD catalogs to help citizens finding available and relevant datasets.
• In the link stage, community participants (industry and academia, for example) help enhance the quality of the released OGD data. Both human power and machine power can be used to generate additional declarative links (such as standard vocabulary, concept mappings, and references to relevant external data) and value-added services (such as automated entity extraction and resolution).
• In the reuse stage, developers pull the published OGD datasets together to build high-value applications. Right now, the value of LOGD deployments is usually exhibited by visual mashups on the Web. In the future, emerging data markets will become the mechanisms that turn the current volunteer value-adding contributions into a profitable business sector.
• "Linked Open Government Data: Lessons from Data.gov.uk" walks through the experience of deploying this public data catalog to illustrate important research challenges in integrating OGD into the linked data Web, and discusses lessons for governments, technical communities, and citizens.
• "US Government Linked Open Data: Semantic.data.gov" is the first official report from the world's largest open government project—Data.gov, operated by the US government. It describes the background of Data.gov as well as the current and planned use of linked data for organizing knowledge and vocabularies within an OGD portal.
• "Harmonization and Interoperability of EU Environmental Information and Services" reports on the ongoing Infrastructure for Spatial Information in the European Community project, whose goal is a highly interoperable cross-border e-environment framework for the European Union. It unveils the designs and recommendations for enabling semantic interoperability via ontologies, thesauri, and spatio-temporal reasoning.
• "Making Research Data Available in Australia" reviews the architecture and experience involved in building the Australian National Data Service, revealing lessons learned from linking government-funded research data.
• "Open Government Data in Brazil" reports on the newborn Brazilian OGD portal and discusses the need for commonly agreed RDF vocabularies in enabling data links and mashups.
• "Recordkeeping and Linking Government Data in Canada" identifies challenges to LOGD based on the experiences in recordkeeping within the government of Canada. It emphasizes the importance of provenance and shows the requirements for sound recordkeeping.
• "Parallel Identities for Managing Open Government Data" presents a solution for provenance tracking in LOGD using a well-established conceptual model: Functional Requirements for Bibliographic Records, from the information science community.
• backlinking, which uses plain rdfs:seeAlso statements to place initial links across OGD datasets and leverage social knowledge by utilizing links provided by the community to semantically enrich the relationships and links among the datasets and concepts;
• data normalization, which relies on automatically learning concept and entity mappings; and
• standardization, which standardizes common metadata and thesauri.
• A million cataloged datasets. In the past few years, an increasing number of government offices, from national to local, have started dedicated websites for cataloging OGD. Finding government data, however, is still challenging to data consumers because of the lack of federation among the catalogs. As of now, Data.gov has already made available around 0.4 million datasets. So, when will there be one million datasets cataloged internationally? Will there be enough universal metadata for finding relevant datasets across the catalogs?
• A million linked datasets. Concept mappings are critical to data mashups, both in mapping vocabularies ("the term state_name is equivalent to st_name") and in aligning entity references ("use dbpedia:Georgia_(U.S._state) instead of the string 'GA'"). Although Data.gov and Data.gov.uk have published many datasets in RDF, there are only a few vocabulary alignments (via rdfs:subPropertyOf, for example) and entity alignments (via owl:sameAs statements). When will there be one million linked datasets, each of which is linked to at least one other dataset? Will the simple dataset catalog eventually evolve into a more collaborative LOGD data market in which users can share data as well as data-processing capability?
• A million LOGD applications. Once it's available as linked data, we certainly want LOGD being delivered to citizens to realize its value. Right now, we see demos, mashups, applications, and portals leveraging LOGD as part of their data sources. When will there be one million applications online that clearly attribute their direct or indirect use of LOGD? Would provenance metadata be more prevalent at that time?