ESWC2024 Trip report

Last week, I joined the 21st edition of the Extended Semantic Web Conference (ESWC2024) held in Heraklion Crete. The 2004 edition was my first scientific conference ever, and I have been going to many editions ever since, so this feels a bit like my ‘home conference’. General Chair Albert Meroño and his team did a great job and it was overall a very nice conference. Paul Groth wrote a very nice trip report here, but I wanted to collect some thoughts and personal highlights in a short blogpost anyway.

The workshops

The workshops overall were very well organized and the ones I joined were well attended. This has been different in previous editions! The PhD symposium was very lively and I had nice chats with PhD candidates during the symposium lunch.

I joined part of the Genesy Workshop, where there were various talks about the potential of generative AI (a definite and unsurprising theme of the conference) and Semantic Web processes and technologies. The paper from Bouchouras et al: LLMs for the Engineering of a Parkinson Disease Monitoring and Alerting Ontology looked at using LLMs for Knowledge Engineering.

I was asked to give a keynote speech at the 2nd edition of the Workshop on Semantic Methods for Events and Stories (SEMMES), at ESWC2024. I talked about work on polyvocality in cultural heritage knowledge graphs. You can find my slides here.

There were very nice talks in the workshop, including the (best paper winning) Let the fallen voussoirs of Notre-Dame de Paris speak: Scientific Narration and 3D Visualization of Virtual Reconstruction Hypotheses and Reasoningfrom Guillem Anais, John Samuel, Gilles Gesquière, Livio De Luca and Violette Abergel that looked at a combination of modelling, argumentation and visualisation for architectural reconstruction.

I then joined the SemDH workshop on Semantic Digital Humanities and its panel discussion in the afternoon, which was really nice. One observation is that many of the talks in SEMMES could have been very interesting for SemDH as well and vice versa. Maybe merging the two would make sense in the future?

The Keynotes

There were three nice keynote speeches, each with its own angle and interesting points.

Elena Simperl gave a somewhat personal history of Knowledge Engineering and the role that machines and humans have in this process. This served as a prelude for the special track on this topic organized by her, Paul Groth and others. Elena called for tools and data for proper benchmarking, introduced the ProVe tool for provenance verification and explored what the roles are of AI (LLM) with respect to Knowledge engineers, domain experts and prompt engineers.

Katariina Kari reflected on 7 Years of Building Enterprise Knowledge Graphs at Zalando and Ikea. This was a very interesting talk about the impact of Knowledge Graphs in industry (she mentioned 7 figure sales increases) and about what works (SKOS, SHACL, OntoClean, Reasoning) and what doesnt work or isnt needed (OWL, Top level ontologies, big data).

Peter Clark of the Allen Institute for AI gave my favorite talk on Structured Reasoning with Language. He discussed their research on Knowledge Graphs and reasoning but also on Belief Graphs, that consist of atomic statements with textual entailment relations. LLMs can be used to ‘reason’ over such Belief Graphs for for example explaining decisions or search results.

Main Conference

The main conference had many interesting talks in all the tracks. The industry track and resource track were quite competitive this year. In terms of quality and number of submissions, they seemed equal to the research track to me this year. Also, the special track on LLMs for Knowledge Engineering was a great success.

I was a bit hesitant with respect to this clear theme of the conference, fearing lots of “we did LLM” talks, but that was not the case at all. Most papers showed genuine interest in the strength and weaknesses of various LLMs and how they can be used in several Semantic web tasks and pipelines. There was clearly a renewed interest in methodologies (Neon, Ontology Engineering 101, Methontology etc ) and how LLMs can fit here. There were for example several talks on how LLMS can be used to generate competency questions: (“Can LLMs Generate Competency Questions? [pdf] by Youssra Rebboud et al. and “The Role of Generative AI in Competency Question Retrofitting” [pdf] by Reham Alharbi et al.”).

Roderick presenting our Resource paper

Roderick van der Weerdt presented our -best Resource paper nominated- OfficeGraph: A Knowledge Graph of Office Building IoT Measurements [pdf]. Roderick did a great job presenting this nice result from the InterConnect project and it was well-received. The winner of the Resource track best paper award was however “PyGraft: Configurable Generation of Synthetic Schemas and Knowledge Graphs at Your Fingertips [pdf] by Nicolas Hubert et al (in my view deservedly so).

The in-use track also had very nice papers, including a quite holistic system to map the German Financial system with knowledge Graphs [pdf] by Markus Schröder et al. Oh, and I won an award 🙂

With more focus on applications, in use, resources, methods for knowledge engineering and of course LLMs, some topics seem to get less attention. Ironically, I missed both Semantics and the Web: Semantics and reasoning did not get a lot of attention in the talks I attended and most applications were about singular knowledge graphs, rather than distributed datasets. Maybe this means that we have solved most of the challenges around these two topics, but possibly it also means that these two elements are less important for actual implementation of Knowledge Graphs. It makes one wonder about the name of the conference though…

With a truly great demo and poster session (near the beach), a great dinner, really nice people and the wonderful surroundings, ESWC2024 was a great success. See you next year in Portoroz!?

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A look back at the HHAI2023 Doctoral Consortium

The next generation of Hybrid-Human-AI researchers are here! As part of the second International Conference on Hybrid Human-Artificial Intelligence that was held in June in Munich, German, myself and Amy Loutfi of Örebro University organized a doctoral consortium. We put out a Call for Papers asking for early to late stage PhD candidates on the topic of Hybrid Human-AI research to submit their research proposals. We received 10 submissions and after a smooth peer-reviewing process we were able to invite 8 participants to the workshop in Munich.

A really nice room for a really nice symposium

The workshop started with a great keynote by Wendy Mackay of Inria, Paris-Saclay, and the Université Paris-Saclay. Wendy is a great authority on Human-Computer Interaction and the relation of that field to Artificial Intelligence and she gave a great talk about the importance of being sensitive to both ends of the AI-HCI scale.

Wendy Mackay

Next, the participants presented their research (plans) in 20 minute presentations, with plenty time for questions and discussions. We were joined by multiple members of the community who provided interesting comments and discussion items after the talks. Each presenter was paired with another participant who would lead the discussion following the presentation. All in all my impression was that this set-up lead to a fruitful and nice atmosphere for in-depth discussions about the research.

The participants of the Doctoral Consortium (from left to right: Anastasiya Zakreuskaya, Johanna Wolff, Dhivyabharathi Ramasamy, Cosimo Palma, Regina Duarte, Victor de Boer, Wendy Mackay, Azade Farshad, Amir Homayounirad, and Nicole Orzan).

Below you find some pictures of the day. The entire programme, including (most of) the papers can be found on the HHAI conference web page. The papers are published by IOS press in the proceedings of the conference: Augmenting Human Intellect.

On behalf of Amy as well: Thank you Azade Farshad, Johanna Wolff, Regina Duarte, Amir Homayounirad, Anastasiya Zakreuskaya, Nicole Orzan, Dhivyabharathi Ramasamy, Cosimo Palma and Wendy Mackay for making the DC work. Thanks as well to the wonderful organization team of HHAI2023 to make everything run so smooth!

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SEMANTiCS 2020 Open Access proceedings

This year’s SEMANTiCS conference was a weird one. As so many other conferences, we had to improvise to deal with the COVID-19 restrictions around travel and event organization. With the help of many people behind the scenes -including the wonderful program chairs Paul Groth and Eva Blomqvist- , we did have a relatively normal reviewing process for the Research and Innovation track. In the end, 8 papers were accepted for publication in this year’s proceedings. The authors were then asked to present their work in pre-recorded videos. These were shown in a very nice webinar, together with contributions from industry. All in all, we feel this downscaled version of Semantics was quite successful.

The Open Access proceedings are published in the Springer LNCS series and are now available at

All presentation videos can be watched at (program/recordings->videos).

And stay tuned for announcements of SEMANTiCS 2021!!

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Semantics2019 trip report

Last week, I attended the SEMANTiCS2019 conference in Karlsruhe, Germany. This was the 15th edition of the conference that brings together Academia and Industry around the topic of Knowledge Engineering and Semantic Technologies and the good news was that this year’s conference was the biggest ever with 426 unique participants.

I was not able to join the workshop day or the dbpedia day on monday and thursday respectively, but was there for the main programme. The first day opened with a keynote from Oracle’s Michael J. Sullivan about Hybrid Knowledge Management Architecture and how Oracle is betting on Semantic Technology to work in combination with data lake architectures.

The 2nd keynote by Michel Dumontier of Maastricht University covered the principles of FAIR publishing of data and current avances in actually measuring FAIRness of datasets.

During one of the parallel sessions I attended the presentation of the eventual best paper winner Robin Keskisärkkä, Eva Blomqvist, Leili Lind, and Olaf Hartig. RSP-QL*: Enabling Statement-Level Annotations in RDF Streams . This was a very nice talk for a very nice and readable paper. The paper describes the combination of current RDF stream reasoning language RSP-QL and how it can be extended with the principles of RDF* that allow for statements about statements without traditional re-ification. The paper nicely mixes formal semantics, an elegant solution, working code, and a clear use case and evaluation. Congratulations to the winners.

Other winners included the best poster, which was won by our friends over at UvA.

The second day for me was taken up by the Special Track on Cultural Heritage and Digital Humanities, which consisted of research papers, use case presentations and posters that relate to the use of Semantic technologies in this domain. The program was quite nice, as the embedded tweets below hopefully show.

All in all, this years edition of SEMANTICS was a great one, I hope next year will be even more interesting (I will be general chairing it).

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Remembering Maarten van Someren

Last week, while abroad, I received the very sad news that Maarten van Someren passed away. Maarten was one of the core teachers and AI researchers at Universiteit van Amsterdam for 36 years and for many people in AI in the Netherlands, he was a great teacher and mentor. For me personally, as my co-promotor he was one of the persons who shaped me into the AI researcher and teacher I am today.

Maarten van Someren at my PhD defense (photo by Jochem Liem)

Before Maarten asked me to do a PhD project under his and Bob Wielinga‘s supervision, I had known him for several years as UvA’s most prolific AI teacher. Maarten was involved in many courses, (many in Machine Learning) and in coordinating roles. I fondly look back at Maarten explaining Decision Trees, the A* algorithm and Vapnik–Chervonenkis dimensions. He was one of the staff members who really was a bridge between research and education and gave students the idea that we were actually part of the larger AI movement in the Netherlands.

After I finished my Master’s at UvA in 2003, I bumped into Maarten in the UvA elevator and he asked me whether I would be interested in doing a PhD project on Ontology Learning. Maarten explained that I would start out being supervised by both him and Bob Wielinga, but that after a while one of them would take the lead, depending on the direction the research took. In the years that followed, I tried to make sure that direction was such that both Bob and Maarten remained my supervisors as I felt I was learning so much from them. From Maarten I learned how to always stay critical about the assumptions in your research. Maarten for example kept insisting that I explain why we would need semantic technologies in the first place, rather than taking this as an assumption. Looking back, this has tremendously helped me sharpen my research and I am very thankful for his great help. I was happy to work further with him as a postdoc on the SiteGuide project before moving to VU.

In the last years, I met Maarten several times at shared UvA-VU meetings and I was looking forward to collaborations in AI education and research. I am very sad that I will no longer be able to collaborate with him. AI in the Netherlands has lost a very influential person in Maarten.

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A look back at UCDS at ICT.Open2018

Two weeks ago, ICT.Open2018 was held in Amersfoort. This event brings together Computer Science researchers from all over the Netherlands and our research group was present with many posters and presentations.

We even won a prize! (Well, a 2nd place prize, but awesome nonetheless). Xander Wilcke presented work on using Knowledge Graphs for Machine Learning. He was awarded the runner-up prize for best poster presentation at ICTOpen2018. Congrats!


Ronald Siebes presented work in the ArchiMediaL project on reconstructing 4D street views from historical images.

Oana Inel presented her work on Named Entity Recognition and Gold Standard critiquing. She also demonstrated the Clariah MediaSuite.

Anca Dumitrache talked about using crowdsourcing as part of the Machine Learning life cycle.

Tobias Kuhn talked about Reliable Granular References to Changing Linked Data, which was previously published at ISWC2017.

Cristina Bucur introduced  Linkflows: enabling a web of linked semantic publishing workflows

I talked myself a bit about current work in the ABC-Kb Network Institute project

All in all, this was quite a nice edition of the yearly event for our group. See you next year in Amersfoort!

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ABC-Kb Network Insitute project kickoff

The ABC-Kb team, clockwise from top-left: Dana Hakman, Cerise Muller, Victor de Boer, Petra BosVU’s Network Institute has a yearly Academy Assistant programme where small interdisciplinary research projects are funded. Within these projects, Master students from different disciplines are given the opportunity to work on these projects under supervision of VU staff members. As in previous years, this year, I also participate as a supervisor in one of these projects, in collaboration with Petra Bos from the Applied Linguistics department. And after having found two enthusiastic students: Dana Hakman from Information Science and Cerise Muller from Applied Linguistics, the project has just started.

Our project “ABC-Kb: A Knowledge base supporting the Assessment of language impairment in Bilingual Children” is aimed at supporting language therapists by (re-)structuring information about language development for bilingual children. Speech language therapists and clinical linguists face the challenge of diagnosing children as young as possible, also when their home language is not Dutch. Their achievements on standard (Dutch) language tests will not be reliable indicators for a language impairment. If diagnosticians had access to information on the language development in the Home Language of these children, this would be tremendously helpful in the diagnostic process.

This project aims to develop a knowledge base (KB) collecting relevant information on the specificities of 60 different home languages (normal and atypical language development), and on contrastive analyses of any of these languages with Dutch. To this end, we leverage an existing wiki:

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Niels’ paper awarded first Bob Wielinga award at EKAW

Niels Ockeloen’s paper on Data2Documents was awarded the first Bob Wielinga memorial award for best research paper at the 20th International Conference on Knowledge Engineering and Knowledge Management (EKAW2016). “Data 2 Documents: Modular and distributive content management in RDF” was authored by Niels Ockeloen, Victor de Boer, Tobias Kuhn and Guus Schreiber from the Web and Media group.. The paper describes Niels’ PhD. work on a method for creating human readable web documents out of machine readable Linked Data, focussing on modularity and re-use. You can view the slides for Niels’ presentation slides here

Niels wins Best Paper Award

The award is named after Prof. Bob Wielinga, one of the most prominent European scientists in the area of knowledge-based systems, best known for his work on the KADS methodology, who has been one of the key influences on the development of the area in the past three decades. Bob was both my own and Guus Schreiber’s promotor so this makes it extra-special for us. In 2009 he was also appointed at our department, where he continued supervising PhD students until he passed away earlier this year. It is especially nice that the award, which was named after Bob Wielinga goes to work that is not only authored by people from Amsterdam but also work that Bob at some point discussed with Niels in the Basket, before his passing.

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I am an Associate Professor (UHD) at the User-Centric Data Science group at the Computer Science department of the Vrije Universiteit Amsterdam (VU) I am also a co-director of the Cultural AI Lab. In my research, I combine (Semantic) Web technologies with Human-Computer Interaction, Knowledge Representation and Information Extraction to tackle research challenges in various domains. These include Cultural Heritage, Digital Humanities and ICT for Development (ICT4D). I am currently involved in the following research projects:

  • HEDGE-IoT: IoT data conversion and enrichment; user-centric and explainable machine learning
  • HAICu: Perspective-aware AI to make digital heritage collections more accessible.
  • InTaVia: making linked cultural heritage and biographical data usable for end-users
  • Pressing Matter: developing data models to support societal reconciliation with the colonial past and its afterlives.
  • Interconnect: machine learning on IoT and smart energy knowledge graphs 
  • Hybrid Intelligence: Augmenting Human Intellect
  • CARPA: responsible production using crowdsourcing in Africa

For other and older research projects, see the “research” tab.

Remembering Bob Wielinga

Yesterday, we received the sad news that Prof. Bob Wielinga passed away. Bob was my promotor and a true mentor to me and many other Dutch AI researchers and he will be sorely missed.

Bob Wielinga at my Ph.D. defense (photo by Jochem Liem)

When I first met Bob as lecturer of the UvA course Knowledge Systems he looked like a ‘real’ professor, with a big white beard and dressed in a dark suit. When later he became my Ph.D. supervisor I found out just how much of a powerhouse he was. He was very humble but at international conferences people mentioned his name with appropriate reverence. He was a very patient and supporting mentor to me and my colleagues and I learned so much from him. Bob was always truly interested in the work of all his students and colleagues, no matter how diverse. He was the only one that could have held such a diverse group of researchers in the SWI group (the later HCS) together.


Artificial Intelligence in the Netherlands has lost one of its greats.


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