Category Archives: development

GSoC2020 – Call for Contribution

James: Sherry with the soup, yes… Oh, by the way, the same procedure as last year, Miss Sophie?

Miss Sophie: Same procedure as every year, James.

…and we are proud of it. We are very grateful to be accepted as an open-source organization in this years’  Google Summer of Code (GSoC2020) edition, again. The upcoming GSoC2020 marks the 16th consecutive year of the program and is the 9th year in a row for DBpedia. 

We did it again – We are mentoring organization!

What is GSoC2020? 

Google Summer of Code is a global program focused on bringing student developers into open source software development. Funds will be given to students (BSc, MSc, PhD.) to work for three months on a specific task. For GSoC-Newbies, this short video and the information provided on their website will explain all there is to know about GSoC2020.

This year’s Narrative

Last year we tried to increase female participation in the program and we will continue to do so this year. We want to encourage explicitly female students to apply for our projects. That being said, we already engaged excellent female mentors to also raise the female percentage in our mentor team. 

In the following weeks, we invite all students, female and male alike, who are interested in Semantic Web and Open Source development to apply for our projects. You can also contribute your own ideas to work on during the summer. 

And this is how it works: 4 steps to GSoC2020 stardom

  1. Open source organizations such as DBpedia announce their projects ideas. You can find our project here
  2. Students contact the mentor organizations they want to work with and write up a project proposal. Please get in touch with us via the DBpedia Forum or dbpedia@infai.org as soon as possible.
  3. The official application period at GSoC starts March, 16th. Please note, you have to submit your final application not through our Forum, but the GSoC Website
  4. After a selection phase, students are matched with a specific project and a set of mentors to work on the project during the summer.

To all the smart brains out there, if you are a student who wants to work with us during summer 2020, check our list of project ideas, warm-up tasks or come up with your own idea and get in touch with us.

Application Procedure

Further information on the application procedure is available in our DBpedia Guidelines. There you will find information on how to contact us and how to appropriately apply for GSoC2020. Please also note the official GSoC 2020 timeline for your proposal submission and make sure to submit on time.  Unfortunately, extensions cannot be granted. Final submission deadline is March 31st, 2020, 8 pm, CEST.

Finally, check our website for information on DBpedia, follow us on Twitter or subscribe to our newsletter.

And in case you still have questions, please do not hesitate to contact us via praetor@infai.org.

We are thrilled to meet you and your ideas.

Your DBpedia-GSoC-Team


New Prototype: Databus Collection Feature

We are thrilled to announce that our Databus Collection Feature for the DBpedia Databus has been developed and is now available as a prototype. It simplifies the way to bundle your data and use it in your application.

A new Databus Collection Feature? How come, and how does it work? Read below and find out how using the DBpedia Databus becomes easier by the day and with each new tool.

Motivation

With more and more data being uploaded to the databus we started to develop test applications using that data. The SPARQL endpoint offers a central hub to access all metadata for datasets uploaded to the databus provided you know how to write SPARQL queries. The metadata includes the download links of the data files – it was, therefore, possible to pass a SPARQL query to an application, download the actual data and then use for whatever purpose the app had.

The Databus Collection Editor

The DBpedia Databus now provides an editor for collections. A collection is basically a labelled SPARQL query that is retrievable via URI. Hence, with the collection editor you can group Databus groups and artifacts into a bundle and publish your selection using your Databus account. It is now a breeze to select the data you need, share the exact selection with others and/or use it in existing or self-made applications.

If you are not familiar with SPARQL and data queries, you can think of the feature as a shopping cart for data: You create a new cart, put data in it and tell your friends or applications where to find it. Quite neat, right?

In the following section, we will cover the user interface of the collection editor.

The Editor UI

Firstly, you can find the collection editor by going to the DBpedia Databus and following the Collections link at the top or you can get there directly by clicking here.

What you will see is the following:

General Collection Info

Secondly, since you do not have any collections yet, the editor has already created an empty collection named “Unnamed” for you. At the right side next to the label and description you will find a pen icon. By clicking the icon or the label itself you can edit its content. The collection is not published yet, so the Collection URI is blank.

Whenever you are not logged in or the collection has not been published yet, the editor will also notify you that your changes are only saved in your local browser cache and NOT remotely on our server. Keep that in mind when clearing your cache. Publishing the collection however is easy: Simply log into (or create) your Databus account and hit the publish button in the action bar. This will open up a modal where you can pick your unique collection id and hit publish again. That’s it!

The Collection Info section will now show the collection URI. Following the link will take you to the HTML representation of your collection that will be visible to others. Hitting the Edit button in the action bar will bring you back to the editor.

Collection Hierarchy

Let’s have a look at the core piece of the collection editor: the hierarchy view. A collection can be a bundle of different Databus groups and artifacts but is not limited to that. If you know how to write a SPARQL query, you can easily extend your collection with more powerful selections. Therefore, the hierarchy is split into two nodes:

  • Generated Queries: Contains all queries that are generated from your selection in the UI
  • Custom Queries: Contains all custom written SPARQL queries

Both, hierarchy nodes have a “+” icon. Clicking on this button will let you add generated or custom queries respectively.

Custom Queries

If you hit the “+” icon on the Custom Queries node, a new node called “Custom Query” will appear in the hierarchy. You can remove a custom query by clicking on the trashcan icon in the hierarchy. If you click the node it will take you to a SPARQL input field where you can edit the query.

To make your collection more understandable for others, you can even document the query by adding a label and description.

Writing Your Own Custom Queries

A collection query is a SPARQL query of the form:

SELECT DISTINCT ?file WHERE {
    {
        [SUBQUERY]
    }
    UNION
    {
        [SUBQUERY]
    }
    UNION
    ...
    UNION
    {
        [SUBQUERY]
    }
}

All selections made by generated and custom queries will be joined into a single result set with a single column called “file“. Thus it is important that your custom query binds data to a variable called “file” as well.

Generated Queries

Clicking the “+” icon on the Generated Queries node will take you to a search field. Make use of the indexed search on the Databus to find and add the groups and artifacts you need. If you want to refine your search, don’t worry: you can do that in the next step!

Once the artifact or group has been added to your collection, the Add to Collection button will turn green. Once you are done you can go back to the Editor with Back to Hierarchy button.

Your hierarchy will now contain several new nodes.

Group Facets, Artifact Facets and Overrides

Group and artifacts that have been added to the collection will show up as nodes in the hierarchy. Clicking a node will open a filter where you can refine your dataset selection. Setting a filter to a group node will apply it to all artifact nodes unless you override that setting in any artifact node manually. The filter set in the group node is shown in the artifact facets in dark grey. Any overrides in the artifact facets will be highlighted in green:

Group Nodes

A group node will provide a list of filters that will be applied to all artifacts of that group:

Artifact Nodes

Artifact nodes will then actually select data files which will be visible in the faceted view. The facets are generated dynamically from the available variants declared in the metadata.

Example: Here we selected the latest version of the databus dump as n-triple. This collection is already in use: The collection URI is passed to the new generic lookup application, which then creates the search function for the databus website. If you are interested in how to configure the lookup application, you can go here: https://github.com/dbpedia/lookup-application. Additionally, there will also be another blog post about the lookup within the next few weeks

Use Cases

The DBpedia Databus Collections are useful in many ways.

  • You can share a specific dataset with your community or colleagues.
  • You can re-use dataset others created
  • You can plug collections into databus-ready applications and avoid spending time on the download and setup process
  • You can point to a specific piece of data (e.g. for testing) with a single URI in your publications
  • You can help others to create data queries more easily

We hope you enjoy the Databus Collection Feature and we would love to hear your feedback! You can leave your thoughts and suggestions in the new DBpedia Forum. Feedback of any kinds is highly appreciated since we want to improve the prototype as fast and user-driven as possible! Cheers!

A big thanks goes to DBpedia developer Jan Forberg who finalized the Databus Collection Feature and compiled this text.

Yours

DBpedia Association

One Billion derived Knowledge Graphs

… by and for Consumers until 2025

One Billion – what a mission! We are proud to announce that the DBpedia Databus website at https://databus.dbpedia.org and the SPARQL API at https://databus.dbpedia.org/(repo/sparql|yasgui) (docu) are in public beta now!

The system is usable (eat-your-own-dog-food tested) following a “working software over comprehensive documentation” approach. Due to its many components (website, SPARQL endpoints, keycloak, mods, upload client, download client, and data debugging), we estimate approximately six months in beta to fix bugs, implement all features and improve the details.

But, let’s start from the beginning

The DBpedia Databus is a platform to capture invested effort by data consumers who needed better data quality (fitness for use) in order to use the data and give improvements back to the data source and other consumers. DBpedia Databus enables anybody to build an automated DBpedia-style extraction, mapping and testing for any data they need. Databus incorporates features from DNS, Git, RSS, online forums and Maven to harness the full work power of data consumers. Vision

Our vision

Professional consumers of data worldwide have already built stable cleaning and refinement chains for all available datasets, but their efforts are invisible and not reusable. Deep, cleaned data silos exist beyond the reach of publishers and other consumers trapped locally in pipelines. Data is not oil that flows out of inflexible pipelines. Databus breaks existing pipelines into individual components that together form a decentralized, but centrally coordinated data network. In this set-up, data can flow back to previous components, the original sources, or end up being consumed by external components.

One Billion interconnected, quality-controlled Knowledge Graphs until 2025

The Databus provides a platform for re-publishing these files with very little effort (leaving file traffic as only cost factor) while offering the full benefits of built-in system features such as automated publication, structured querying, automatic ingestion, as well as pluggable automated analysis, data testing via continuous integration, and automated application deployment (software with data). The impact is highly synergistic. Just a few thousand professional consumers and research projects can expose millions of cleaned datasets, which are on par with what has long existed in deep silos and pipelines.

To a data consumer network

As we are inverting the paradigm form a publisher-centric view to a data consumer network, we will open the download valve to enable discovery and access to massive amounts of cleaner data than published by the original source. The main DBpedia Knowledge Graph alone has 600k file downloads per year complemented by downloads at over 20 chapters, e.g. http://es.dbpedia.org as well as over 8 million daily hits on the main Virtuoso endpoint.

Community extension from the alpha phase such as DBkWik, LinkedHypernyms are being loaded onto the bus and consolidated. We expect this number to reach over 100 by the end of the year. Companies and organisations who have previously uploaded their backlinks here will be able to migrate to the databus. Other datasets are cleaned and posted. In two of our research projects LOD-GEOSS and PLASS, we will re-publish open datasets, clean them and create collections, which will result in DBpedia-style knowledge graphs for energy systems and supply-chain management.

A new era for decentralized collaboration on data quality

DBpedia was established around producing a queryable knowledge graph derived from Wikipedia content that’s able to answer questions like “What have Innsbruck and Leipzig in common?” A community and consumer network quickly formed around this highly useful data, resulting in a large, well-structured, open knowledge graph that seeded the Linked Open Data Cloud — which is the largest knowledge graph on earth. The main lesson learned after these 13 years is that current data “copy” or “download” processes are inefficient by a magnitude that can only be grasped from a global perspective. Consumers spend tremendous effort fixing errors on the client-side. If one unparseable line needs 15 minutes to find and fix, we are talking about 104 days of work for 10,000 downloads. Providers – on the other hand – will never have the resources to fix the last error as cost increases exponentially (20/80 rule). 

One billion knowledge graphs in mind – the progress so far

Discarding faulty data often means that a substitute source has to be found, which is hours of research and might lead to similar problems. From the dozens of DBpedia Community meetings we held we can summarize that for each clean-up procedure, data transformation, linkset or schema mapping that a consumer creates client-side, dozens of consumers have invested the same effort client-side before him and none of it reaches the source or other consumers with the same problem. Holding the community meetings just showed us the tip of the iceberg. 

As a foundation, we implemented a mappings wiki that allowed consumers to improve data quality centrally. A next advancement was the creation of the SHACL standard by our former CTO and board member Dimitris Kontokostas. SHACL allows consumers to specify repeatable tests on graph structures and datatypes, which is an effective way to systematically assess data quality. We established the DBpedia Databus as a central platform to better capture decentrally created, client-side value by consumers.

It is an open system, therefore value that is captured flows right back to everybody.  

The full document “DBpedia’s Databus and strategic initiative to facilitate “One Billion derived Knowledge Graphs by and for Consumers” until 2025 is available here.  

If you have any feedback or questions, please use the DBpedia Forum, the “report issues” button, or dbpedia@infai.org.

Yours,

DBpedia Association

DBpedia Forum – New Ways to Exchange about DBpedia

From now on, in addition to our newsletter and slack as a means for communication, we have a new platform for exchange and support around DBpedia – the DBpedia Forum.

With part  II of our growth hack series, we would like to introduce you to the latest feature of our development – the new DBpedia Forum.

Why a new forum?

DBpedia has an inclusionist model and DBpedia is huge. At the core, there is data extracted from Wikipedia and Wikidata. Around this, there are derived datasets like the fusion/enrichment and also LHD. Additionally, we offer services such as DBpedia Spotlight, DBpedia Lookup, SameAs, and not to forget the main endpoint http://dbpedia.org/sparql as well as our DBpedia Chapters. All of this is surrounded by 25k academic papers and a vivid business network.

Since we have this inclusionist model, we believe that access to data and knowledge should be global and unified (and free where possible). That is exactly why we established the DBpedia Forum –  to further this mission. 

Welcome!

The DBpedia Forum is a shared community resource — a place to share skills, knowledge, and interests through an ongoing conversation about DBpedia and related topics. It is meant (among others) to replace our old support page for assistance with DBpedia. In the long run, we will shut down our (former) support page, as it is not serving our growing needs anymore. 

This is what the forum currently looks like. Traffic and communication are still a little low. Start your conversation about DBpedia here and now.

Where are all the DBpedians?

We figured, most of you are already actively involved in exchange about DBpedia. However, the majority of that is scattered all over the web which makes it hard for us and others to keep track of. With the new forum, we offer you a playground for vivid exchange, and to meet and greet fellow DBpedians – a platform for everyone’s benefit. 

The DBpedia Forum simplifies communication

Make this a great place for discussion by contributing yourself. It is super easy. Just visit https://forum.dbpedia.org/, browse the topics, and find the info that helps you or add your own. If you want to contribute just register and off you go. Improve the discussion by discovering ones that are already happening. Help us influence the future of the DBpedia community by engaging in discussions that make this forum an interesting place to be. 

Transparency is all

To assist with maintaining an appropriate code of conduct the forum utilizes little discourse tools that enable the community to collectively identify the best (and worst) contributions. The forum tracks bookmarks, likes, flags, replies, edits, and many more. That is similar to the ranking in the old support system but much more transparent and much more fun.

For the hunter-gatherers among you, you can also earn batches for various activities  – as long as you are active.  And if you feel very passionate about a certain topic, we would gladly make you a moderator – just let us know.  

Now is the time

Since you are already talking about DBpedia somewhere on the WWW, why not do it here and now for everyone else to follow? Your knowledge and skills are key, not only for individuals in this forum but also for the whole DBpedia community. 

Happy posting and stay tuned for part III in the growth hack series. The next post will feature timbr – DBpedia SQL Semantic Knowledge Platform.

Yours,

DBpedia Association

DBpedia Growth Hack – Fall/Winter 2019

*UPDATE* – We are now 5 weeks in our growth hack. Read on below to find out how it all started. Click here to follow up on each of our milestones.

A growth hack – how come?

Things have gone a bit quiet around DBpedia. No new releases, no clear direction to go. Did DBpedia stop? Actually not. There were community and board member meetings, discussions, 500 messages per week on dbpedia.slack.com.

We are still there. We, as a community, restructured and now we are done, which means that DBpedia will now work more focused to build on its Technology Leadership role in the Web of Data and thus – with our very own DBpedia Growth Hack – bring new innovation and free fuel to everybody.

What is this growth hack?

We restructured in two areas:

  1. The agility of knowledge delivery –  our release cycle was too slow and too expensive. We were unable to include substantial contributions from DBpedians. Therefore, quality and features stagnated.
  2. Transparent processes – DBpedia has a crafty community with highly skilled knowledge engineers backing it. At some point, we grew too much and became lumpy, with a big monolithic system that nobody could improve because of side effects. So we designed a massive curation infrastructure where information can be retrieved, adjusted and errors discussed and fixed.

We have been consistently working on this restructuring for two years now and we now have the infrastructure ready as horizontal prototype meaning each part works and everybody can start using it. We ate our own dog food and built the first application.

(Frey et al. DBpedia FlexiFusion – Best of Wikipedia > Wikidata > Your Data (accepted at ISWC 2019) .

Now we will go through each part and polish & document it, and will report about it with a blog post each.  Stay tuned !

Is DBpedia Academic or Industrial?

The Semantic Web has a history of being labelled as too academic and a part of it colored DBpedia as well. Here is our personal truth: It is an engineering project and therefore it swings both ways. It is a great academic success with 25,000 papers using the data and  enabling research and innovation. The free data drives research on data-driven research. Also, we are probably THE fastest pathway from lab to market as our industry adoption has unprecedented speed. Proof will follow in the blog posts of the Growth Hack series.

Blog Posts of the Growth Hack series:

(not necessarily in that order, depending on how fast we can polish & document )

  • Query DBpedia as SQL – a first service on the Databus
  • DBpedia Live Extraction – Realtime updates of Wikipedia
  • DBpedia Business Models – How to earn money with DBpedia & the Databus
  • MARVIN Release Bot – together with https://blogs.tib.eu/wp/tib/ incl. an update of https://wiki.dbpedia.org/Datasets
  • The new forum https://forum.dbpedia.org is already ready to register, but needs some structure. Intended as replacement of support.dbpedia.org

In addition some announcements of on-going projects:

  • GlobalFactSync (GFS)Syncing facts between Wikipedia and Wikidata
  • Energy Databus: LOD GEOSS project focusing on energy system data on the bus
  • Supply-Chain-Management Databus – PLASS project focusing on SCM data on the bus

So, stay tuned for our upcoming posts and follow our journey.

Yours

DBpedia Association