Following, we will give you a brief retrospective about the presentations.

Opening Session

Katja Hose – “Querying the web of data”

….on the search for the killer App.

The concept of Linked Open Data and the promise of the Web of Data have been around for over a decade now. Yet, the great potential of free access to a broad range of data that these technologies offer has not yet been fully exploited. This talk will, therefore review the current state of the art, highlight the main challenges from a query processing perspective, and sketch potential ways on how to solve them. Slides are available here.

Dan Weitzner – “timbr-DBpedia – Exploration and Query of DBpedia in SQL”

The timbr SQL Semantic Knowledge Platform enables the creation of virtual knowledge graphs in SQL. The DBpedia version of timbr supports query of DBpedia in SQL and seamless integration of DBpedia data into data warehouses and data lakes. We already published a detailed blogpost about timbr where you can find all relevant information about this amazing new DBpedia Service.

Showcase Session

Maribel Acosta – “A closer look at the changing dynamics of DBpedia mappings”

Her presentation looked at the mappings wiki and how different language chapters use and edit it. Slides are available here.

Mariano Rico – “Polishing a diamond: techniques and results to enhance the quality of DBpedia data”

DBpedia is more than a source for creating papers. It is also being used by companies as a remarkable data source. This talk is focused on how we can detect errors and how to improve the data, from the perspective of academic researchers and but also on private companies. We show the case for the Spanish DBpedia (the second DBpedia in size after the English chapter) through a set of techniques, paying attention to results and further work. Slides are available here.

Guillermo Vega-Gorgojo – “Clover Quiz: exploiting DBpedia to create a mobile trivia game”

Clover Quiz is a turn-based multiplayer trivia game for Android devices with more than 200K multiple choice questions (in English and Spanish) about different domains generated out of DBpedia. Questions are created off-line through a data extraction pipeline and a versatile template-based mechanism. A back-end server manages the question set and the associated images, while a mobile app has been developed and released in Google Play. The game is available free of charge and has been downloaded by +10K users, answering more than 1M questions. Therefore, Clover Quiz demonstrates the advantages of semantic technologies for collecting data and automating the generation of multiple-choice questions in a scalable way. Slides are available here.

Fabian Hoppe and Tabea Tiez – “The Return of German DBpedia”

Fabian and Tabea will present the latest news on the German DBpedia chapter as it returns to the language chapter family after an extended offline period. They will talk about the data set, discuss a few challenges along the way and give insights into future perspectives of the German chapter. Slides are available here.

Wlodzimierz Lewoniewski and Krzysztof Węcel  – “References extraction from Wikipedia infoboxes”

In Wikipedia’s infoboxes, some facts have references, which can be useful for checking the reliability of the provided data. We present challenges and methods connected with the metadata extraction of Wikipedia’s sources. We used DBpedia Extraction Framework along with own extensions in Python to provide statistics about citations in 10 language versions. Provided methods can be used to verify and synchronize facts depending on the quality assessment of sources. Slides are available here.

Wlodzimierz Lewoniewski – “References extraction from Wikipedia infoboxes” … He gave insight into the process of extracting references for Wikipedia infoboxes, which we will use in our GFS project.

Afternoon Session

Sebastian Hellmann, Johannes Frey, Marvin Hofer – “The DBpedia Databus – How to build a DBpedia for each of your Use Cases”

The DBpedia Databus is a platform that is intended for data consumers. It will enable users to build an automated DBpedia-style Knowledge Graph for any data they need. The big benefit is that users not only have access to data, but are also encouraged to apply improvements and, therefore, will enhance the data source and benefit other consumers. We want to use this session to officially introduce the Databus, which is currently in beta and demonstrate its power as a central platform that captures decentrally created client-side value by consumers.  

We will give insight on how the new monthly DBpedia releases are built and validated to copy and adapt for your use cases. Slides are available here.

Interactive session, moderator: Sebastian Hellmann – “DBpedia Connect & DBpedia Commerce – Discussing the new Strategy of DBpedia”

In order to keep growing and improving, DBpedia has been undergoing a growth hack for the last couple of months. As part of this process, we developed two new subdivisions of DBpedia: DBpedia Connect and DBpedia Commerce. The former is a low-code platform to interconnect your public or private databus data with the unified, global DBpedia graph and export the interconnected and enriched knowledge graph into your infrastructure. DBpedia Commerce is an access and payment platform to transform Linked Data into a networked data economy. It will allow DBpedia to offer any data, mod, application or service on the market. During this session, we will provide more insight into these as well as an overview of how DBpedia users can best utilize them. Slides are available here.

In case you missed the event, all slides and presentations are also available on our Website. Further insights, feedback and photos about the event are available on Twitter via #DBpediaDay

We are now looking forward to more DBpedia meetings next year. So, stay tuned and check Twitter, Facebook and the Website or subscribe to our Newsletter for the latest news and information.

If you want to organize a DBpedia Community meeting yourself, just get in touch with us via dbpedia@infai.org regarding program and organization.

Yours

DBpedia Association

The post More than 50 DBpedia enthusiasts joined the Community Meeting in Karlsruhe. appeared first on DBpedia Association.

How is data edited in Wikipedia/Wikidata? Where does it come from? And how can we synchronize it globally?  

The GlobalFactSync (GFS) Project — funded by the Wikimedia Foundation — started in June 2019 and has two goals:

• Answer the above-mentioned three questions.
• Build an information system to synchronize facts between all Wikipedia language-editions and Wikidata. 

Now we are seven weeks into the project (10+ more months to go) and we are releasing our first prototypes to gather feedback. 

How – Synchronization vs Consensus

We follow an absolute “Human(s)-in-the-loop” approach when we talk about synchronization. The final decision whether to synchronize a value or not should rest with a human editor who understands consensus and the implications. There will be no automatic imports. Our focus is to drastically reduce the time to research all references for individual facts.

A trivial example to illustrate our reasoning is the release date of the single “Boys Don’t Cry” (March 16th, 1989) in the English, Japanese, and French Wikipedia, Wikidata and finally in the external open database MusicBrainz.  A human editor might need 15-30 minutes finding and opening all different sources, while our current prototype can spot differences and display them in 5 seconds.

We already had our first successful edit where a Wikipedia editor fixed the discrepancy with our prototype: “I’ve updated Wikidata so that all five sources are in agreement.” We are now working on the following tasks:

• Scaling the system to all infoboxes, Wikidata and selected external databases (see below on the difficulties there)
• Making the system:
  •  “live” without stale information
  • “reliable” with less technical errors when extracting and indexing data
  • “better referenced” by not only synchronizing facts but also references 

Contributions and Feedback

To ensure that GlobalFactSync will serve and help the Wikiverse we encourage everyone to try our data and micro-services and leave us some feedback, either on our Meta-Wiki page or via email. In the following 10+ months, we intend to improve and build upon these initial results. At the same time, these microservices are available to every developer to exploit it and hack useful applications. The most promising contributions will be rewarded and receive the book “Engineering Agile Big-Data Systems”. Please post feedback or any tool or GUI here. In case you need changes to be made to the API, please let us know, too.
For the ambitious future developers among you, we have some budget left that we will dedicate to an internship. In order to apply, just mention it in your feedback post. 

Finally, to talk to us and other GlobalfactSync-Users you may want to visit WikidataCon and Wikimania, where we will present the latest developments and the progress of our project. 

Data, APIs & Microservices (Technical prototypes) 

Data Processing and Infobox Extraction

For GlobalFactSync we use data from Wikipedia infoboxes of different languages, as well as Wikidata, and DBpedia and fuse them to receive one big, consolidated dataset – a PreFusion dataset (in JSON-LD). More information on the fusion process, which is the engine behind GFS, can be found in the FlexiFusion paper. One of our next steps is to integrate MusicBrainz into this process as an external dataset. We hope to implement even more such external datasets to increase the amount of available information and references. 

First microservices 

We deployed a set of microservices to show the current state of our toolchain.

• [Initial User Interface] The GlobalFactSync UI prototype (available at http://global.dbpedia.org) shows all extracted information available for one entity for different sources. It can be used to analyze the factual consensus between different Wikipedia articles for the same thing. Example: Look at the variety of population counts for Grimma.

• [PreFusion JSON API] While the UI allows simple, fast and easy browsing for one entity at a time, we also provide raw access to the underlying data (PreFusion dump). The query UI (http://global.dbpedia.org:8990 (user: read, pw: gfs) can be utilized to run simple analytical queries. Thus, we can determine the number of locations having at least one population value (1,194,007) but can also focus on examples with data quality problems (e.g. one of the 4,268 locations with more than 10 population values). Moreover, documentation about the PreFusion dataset and the download link for the data are available on the Databus website. 

• [Reference Data Download] We ran the Reference Extraction Service over 10 Wikipedia languages. Download dumps here.

• [Reference Extraction Service] Good references are crucial for an import of facts from Wikipedia to Wikidata. We are currently working with colleagues from Poznań University of Economics and Business on reference extraction for facts from Wikipedia. A current development reference extraction microservice shows all references and the location where they were spotted in the Infobox – ad hoc – for a given article: http://dbpedia.informatik.uni-leipzig.de:8111/infobox/references?article=https://en.wikipedia.org/wiki/Facebook&format=json  ( ‘&format=tsv’ also available) 

• [Infobox Extraction Service] A similar ad hoc extraction of factual information from infoboxes and other Wikipedia article information is available here. This microservice displays information which can be extracted with the help of DBpedia mappings from an infobox e.g. from the German Facebook Wikipedia article: http://dbpedia.informatik.uni-leipzig.de:9998/server/extraction/en/extract?title=Facebook&revid=&format=trix&extractors=mappings. See here for more options: http://dbpedia.informatik.uni-leipzig.de:9999/server/extraction/.

• [ID service] Last but not least, we offer the Global ID Resolution Service. It ties together all available identifiers for one thing (i.e. at the moment all DBpedia/Wikipedia and Wikidata identifiers – MusicBrainz coming soon…) and shows their stable DBpedia Global ID. 

Finding sync targets

In order to test out our algorithms, we started by looking at various groups of subjects, our so-called sync targets. Based on the different subjects a set of problems were identified with varying layers of complexity:

• identity check/check for ambiguity — Are we talking about the same entity? 
• fixed vs. varying property — Some properties vary depending on nationality (e.g., release dates), or point in time (e.g., population count).
• reference — Depending on the entity’s identity check and the property’s fixed or varying state the reference might vary. Also, for some targets, no query-able online reference might be available.
• normalization/conversion of values — Depending on language/nationality of the article properties can have varying units (e.g., currency, metric vs imperial system).

The check for ambiguity is the most crucial step to ensure that the infoboxes that are being compared do refer to the same entity. We found, instances where the Wikipedia page and the infobox shown on that page were presenting information about different subjects (e.g., see here).

Examples

As a good sync target to start with the group ‘NBA players’ was identified. There are no ambiguity issues, it is a clearly defined group of persons, and the amount of varying properties is very limited. Information seems to be derived from mainly two web sites (nba.com and basketball-reference.com) and normalization is only a minor issue. ‘Video games’ also proved to be an easy sync target, with the main problem being varying properties such as different release dates for different platforms (Microsoft Windows, Linux, MacOS X, XBox) and different regions (NA vs EU).

More difficult topics, such as ‘cars’, ’music albums’, and ‘music singles’ showed more potential for ambiguity as well as property variability. A major concern we found was Wikipedia pages that contain multiple infoboxes (often seen for pages referring to a certain type of car, such as this one). Reference and fact extraction can be done for each infobox, but currently, we run into trouble once we fuse this data. 

Further information about sync targets and their challenges can be found on our Meta-Wiki discussion page, where Wikipedians that deal with infoboxes on a regular basis can also share their insights on the matter. Some issues were also found regarding the mapping of properties. In order to make GlobalFactSync as applicable as possible, we rely on the DBpedia community to help us improve the mappings. If you are interested in participating, we will connect with you at http://mappings.dbpedia.org and in the DBpedia forum.  

Bottomline – We value your feedback

Your DBpedia Association

The post Global Fact Sync – Synchronizing Wikidata & Wikipedia’s infoboxes appeared first on DBpedia Association.