What did you do in your PhD? – ECER 2021

I held a short presentation at ECER 2021, which was online due to the pandemic. This presentation gives a good overview about my PhD work. You can also find the abstract and the slides. I also created a teaser.

In short, I developed an ontology or a metadata set for qualitative coding schemas. This ontology helps to make these coding schemas easier to find and reuse. It also helps to make them more comparaeble and finally to encourage researchers to describe what they did in more detail.

I also did some additional research how high the acceptance rate by researchers for such a transformation is. This also lead to the question, how to overcome the barriers researchers see in open science. The barriers were similar to barriers about open science in other fields, like more effort or

If you want to dive deeper into the work, see my GitHub with the ontology and links to publications.


Roman Mars – The 99% invisible city

I really love the podcast 99% invisible that deals with design. Therefore I was excited when they announced a book about hidden design in cities. The book copies the aim of the podcast to make the invisble visible and point the reader to design in cities and the cool stories behind it. It is divided up into several chapters like Infrastructure, Geography or Architecture, that are then also divided up into smaller parts. For instance, the chapter Infrastructure is divided up into Civic, Water, Technology and Roadways.

In each of these sub-chapters you find detailed descriptions of one phenomenon. These descriptions are each one to two pages long, which makes the book easy to read and also makes it a resource that you can read later again.You also do not have to read it from the beginning to end although sometimes there are cross-references.

I really liked to read all the stories of small things you recognize in cities. However, the book is mainly focused on cities in the US. It is also fascinating to see that some of the design concepts are only visible in on or two cities, often due to some historical events or habits.

It is a nice book, can be also used very well as a present. It has really nice illustrations and it looks really significant. You can also use it as a guideline where you can later look at it and find our cool things that are visible in your city. The subtitle is A field guide to the hidden world of everyday design. This describes it best. Take the guide and see what you can see in the field!


Citizen Science in research about schoolbooks

As some of you know, we started the project Interlinking Pictura some time ago. We also published an article about this as Bridging citizen science and open educational resources at OpenSym 2018 (DOI: This was a rather technical article about the project and how we wanted to integrate citizen science. Later, some collegues asked, if we wanted to make an article for a non-technical audience about our citizen science project.

In our new publication, we present potentials for citizen science in the field of history of education. It does not go deeply into our research, but gives an overview on projects in the field and what we tried and learned. So it might be a good start for your citizen science project in digital humanities. You can find the article “Potenziale von Citizen Science in der historischen Schulbuchforschung. Das Beispiel Interlinking Pictura” at


From project to infrastructure – the Schularchive-Wiki project funded by the Fellow Program Free Knowledge

The continuation of the Schularchive-Wiki within the framework of the Fellow-Program Free Knowledge.

I wrote this text to reflect on the Fellow-Programm together with my mentor Maximilian Heimstädt. It was first published at the blog of Wikimedia Germany.

The Project

As part of the Fellow Program Free Knowledge, the project Schularchive (school archives) was funded. This project aims to collect historical sources for school research and make them available to all interested parties and researchers. Such sources are often very difficult to find, often only through personal contacts. Schularchivewants to solve this problem and thus also contribute to better equal opportunities within research.

We see the project Schularchive primarily as an infrastructure on which researchers can document their research sourceand thus build up synergy effects in this research of sources in the sense of Open Science. In addition, we help to make the holdings in state, regional, and school archives more widely known.

At the beginning of the Fellow Program, the platform was already available as a prototype. Within the framework of the Fellow Program Free Knowledge, we carried out various activities. These served primarily to raise awareness of the project and to involve more people:

  • Two workshops (Fall 2020 and Spring 2021)
  • Establishment of a Twitter channel @Schularchive.
  • Importing data from state archives. Contact with the various state archives was also made through the workshops. Currently, only data from the state archives of Baden-Württemberg are on the platform; in the next few weeks, data from Bavaria will also be added, after which other archives will be requested.
  • The link to data from Wikidata was further expanded. In the meantime, a lot of data such as pictures, foundation and web pages of schools are taken over from Wikidata. The link to other sources such as the German National Library is currently being pursued further as part of a student project.


After half a year on Twitter, we have about 60 followers. This is not very many, but also not too bad, since the community is relatively small. However, the project is already very well known within the community of historical educational research and through the workshops we were able to establish contacts with state archives and school archivists. In addition, we presented the project at various academic conferences. The workshops, on the other hand, proved to be very useful for imparting knowledge, getting feedback, but also as an advertisement for the project to attract new interested people. The goal of establishing more contacts with schools proved difficult due to the COVID-19 pandemic.

In principle, we would also like to see a deeper integration and further development of the platform in the historical education research community. During the workshops, useful suggestions always came up, which we gladly took up. It would also be nice to build up the community permanently. At the same time, it became clear to us that this would be difficult, since most of the potential contributors are also involved in other projects. A good possibility is therefore to market Schularchive more as a tool for Open Science in research projects in order to get more people on the platform.

Future Plans

After the end of the Fellow Program Free Knowledge, we would like to write a proposal to further advance the project. In addition, through networking, we were also able to convince various other research teams to use our platform for their research, so that indirect funding is also possible through it. This two-pronged approach makes sense, as not all research proposals are approved and in the case of infrastructures, often only large projects are funded. However, the community of historical education research is not that large. At the same time, we do not think it makes much sense to make such an infrastructure the responsibility of a few people within the institutions. This is because there is also the risk that a lot of knowledge will be lost when people change or that the platform will die completely. It is also important to us that the connection to the community remains firmly established, which is ensured by the Library for Research on the History of Education of the DIPF and the department “Historical Educational Research” of the Ruhr University Bochum.

Lessons Learned

The project showed us that three points in particular are very important in order to perpetuate open science projects:

  1. Sustainability Try to locate the infrastructure within an institution that has an interest in the project. In addition, funding through other projects is useful.
  2. Involvement in subject community Involve your project in the subject community and enable easy participation, for example by providing OER on your project.
  3. Create publicity Make your project more known, we used Twitter, workshops and social contacts for this, but there are many more. This will make you more known and show that the project is important. You will also find people who want to participate and maybe even raise money for you.

ECER 2021 pre-conference presentation

I am happy to present my work for the ontology QualiCO (my phd project) at ECER 2021. Watch my pre-conference presentation on Youtube.


Evaluation of German open data portals

In the last years, many cities and states in Germany built up portals where they publish data, for instance about how they spend money, to an overview of the trees in their city. This Open government data is becoming more and more important. First, transparency of public institutions is always important and second, data-driven services might be able to use this data in a great way.

In this publication we evaluated how well the open data portals of the largest German cities and states are doing with the focus on educational data. Our findings are:

  • most portals already use open licences
  • but many portals do not use machine-readable formats like csv, they rather rely on PDF
  • Not all portals use metadata standards
  • Many cities do not share the projects being created with their data
  • There is not one portal which is best in all categories
  • Many cities do not have open data portals yet

We presented this at ISI 2021, you can find the article at

General Science

Reflections on my PhD

In this post I want to write down what I learned during my PhD and what might help you too. It is my opinion on the stuff, but I used all of the techniques I described and they helped me. I split this up into four parts: Before you start, finding a supervisor, writing and finishing.

Why start a PhD?

When I thought about starting a PhD I had the motivation that I liked scientific work. I had done internships and work as a student in companies, but I wanted to dive deeper into research and learn more about the stuff I learned at university.

I also had in mind that a PhD is normally not a bad thing for your career. However, you might earn in a well-paid industry job at least at the beginning more money than in your PhD. And if you really only do it for the title, the time doing it might be really hard for you.

All this depends a lot on the field. Take a look at people you know in the field that archived things you want to archive and see what they did to get there. For me it made sense, since I was interested to get deeper knowledge about the field and could imagine to become a professor.

Finding a supervisor

In German the relationship to your supervisor is really close, you even call them your doctoral mother or doctoral father. But this also shows one issue you should be aware of: Your PhD depends a lot on these people. So choose them wisely!

So, how do you find a supervisor? In my case, I knew some of supervisors before, in fact I wrote my master‘s thesis in their department. My third supervisor I did not know before. Since the relationship to these people is really strong and you depend on them, I would encourage you to choose supervisors you get along with. Three (or four, five, six) years can be a hard time if you hate your supervisor or vice-versa. Also, it might make sense to not join the most prestigious university but get better support (Although you need some balancing in this since your degree might help you afterwards with finding a better job).

Another thing you should keep in mind is that also your supervisor does not know everything. I did my PhD in the very interdisciplinary field of open science, information science, ontology engineering and human-centered design, so I constantly needed to get feedback from other people and I was very lucky to meet a lot of helpful people. I was also happy for some workshops and courses about scientific methods like interviews I did not know a lot before. I also got really valuable feedback from the folks at University of Washington as well as unexpected places like the peer review of some of my articles. Conferences with PhD-sessions are also a great place for this, although I did not attend a lot of these. I also used the PhD programme at the University of Frankfurt a lot, since they provide a lot of helpful workshops about scientific methods, project management and other topics you might need for you dissertation.


Write drafts

Since I had several supervisors who do not all work at the same institution, I had to do a lot of communication between them. What helped me here, was to write a summary of the next steps I would do in my process and send this to them before the meetings. This takes of course some effort, but it allows your supervisors to know what you are doing and your agreements are more precise if you send them some text before meeting than just presenting your content. I tried this at first, but it did not work out. The other great advantage is if you wrote down your next steps, you are already done with some parts of your thesis!

Start early

Based on this, I also started writing up my analysis as soon as I did it. Since I used a multi-level design process, this was crucial anyway to get to the next step. The disadvantage was that I had to do a lot of reworking at the end.

Start with something easy

You won‘t write your thesis from the beginning to the end. Therefore, start with an easy part and go from there. My order was (with a lot of going back and forth): method – literature – results – discussion – introduction – conclusion. You might start with some other part, but this is your work, so make it comfortable for you.

Make a plan of each chapter

What also helped me a lot was to make a plan what I wanted to say in each chapter. This helps you to keep the red line within your work. The plan can also change during the process, but most of the plan will stay the same and helps you to navigate through the work. Keep in mind that your thesis will most likely be longer than 150 pages, so it is impossible (at least if was impossible for me) to keep an easy overview. The plan can also help you to keep track about your progress and helps finding chapters where you need to focus more on


I used LaTeX to write my thesis. This was because I used LaTeX before in my master’s thesis. The advantages are that you do not have to worry about a document crashing and being unreadable, backups are also very easy, LaTeX takes care of your citations and the final product looks quite nice. A disadvantage is that it does not provide a nice track changes function like Word. My proofreaders wanted to work in Word, so I had to copy back from a Word document to my LaTeX files, which took a lot of time. But you also have to keep in mind that even if your proofreaders use track changes, you have to check all the document again, which might be very time-consuming.


The finishing might be the hardest part. You are really stressed and see that things did not make that much sense as you thought at the beginning. There are also a lot of distractions out there and your funding might run out. My last phase of the PhD was not normal, since I did it during the Covid-19 pandemic.

Stop other stuff

The good thing is science is that many people you work with went through a PhD. So they will know that you are really busy at your finishing phase and hopefully leave you alone in that time. I was really shocked when I recognized how much more productive I was when I did not have any meetings at a given day. One good way is to move all the meetings you have to one day, so you won‘t be very productive that day, but all the other days.

Get a routine

As soon as you managed to be free from other day-to-day work, you might want to enjoy your free time. Of course, this makes it harder. During Covid-19, I learned to be way more organized, therefore this was relatively easy for me. Also, a lot of distractions were not possible, so I focused on the thesis. It also helps to have a plan and some milestones, so you keep track what you have finished and what is left to do.

Schedule breaks

If you created a plan, do not be too hard to yourself. You need breaks. For a certain time (this might be shorter than you think) you can work day and night without breaks. But if you are sick afterwards, your productivity drops. My approach therefore was to have a strict plan from the beginning where I can get easier and also have some time a the end for unknown events. So I had a relaxed time finishing my first draft. However, I was really stressed four weeks before in order to get the first draft done for some friends to read over it


The end of the Information Age?

Last week there was this really interesting article at Heise online, a German tech magazine. It calls for the end of the modern internet, putting it into a postmodern internet. This also tackles the value of information and it’s declining in a postmodern age.

In the traditional way, we talk in information science a lot about the governance of information. The idea behind is in my opinion based on a library: In a library, the goal is to have as much information (books) available as possible in order to give them to people. They read the books and become smarter. At the same time, you know that the books are still kind of expensive, so your ideal is that all books should be free for everyone to read. Then everyone can get smarter and everything will be better.

With the internet, this happened. The only thing that did not happen was that people went to this new library and got the most relevant books. At that time, we as information scientists stepped in and said: „You have to make sure only people who are well-respected can write books in your library and we can teach you how to see this and educate you.“ The issue here was: it was not so easy to find out who is this credible source. It takes a lot of time to learn this and simple heuristics do not work. In science, we use peer-review to make sure we only publish what makes sense, but this also has some flaws.

After this, another phase started: The age of Wikipedia. The promises came true, everyone was able to edit it (although you were more likely to do it if you are a privileged nerd). You had less gatekeepers, but cheap information at a very high level. This idea was so successful that social networks came up, driving this even further: now really everyone with an account was able to publish stuff, get followers and so on. At the same time, the incentives for keeping people at the platform rose in order to bomb them with ads. This had the advantage that people were able to make a living from YouTube, but also people getting highly rewarded for posting conspiracy theories and hate comments.

Another thing happened: Information got so cheap that even if I do not find someone who shares information I like, I can just introduce my own source of information and a „market“ will make sure that the best source wins. The end of this was that the platforms won who were best at selling our attention to ad-companies. And the best way to get our attention seems to be lies (please stop calling it fake-news).

In my opinion, the question of how to fix this is extremely relevant to information science. I do not think we can fix this with better automatic moderating or censoring. There is way too much information out there to do this. We also saw that when Twitter blocked the account of Donald Trump, he started using the next platform.

I see two main barriers in this: first, we do not want to have censorship with old gatekeepers, be it a nation-state, a company or some kind of weird guy at Wikipedia. Second, I also do not see this happen since all of this costs a lot of money. If you have people checking for it, you have to pay them, if an algorithm does it, you have to take care of the errors, if volunteers do it, you create the same hierarchies of gatekeepers you wanted to avoid in the first place.

Therefore I am really curious what comes next. I also think from a theoretical perspective this is very interesting to look and maybe go further to create approaches that work.


Fellowship Free Knowledge

I am happy to announce that I got accepted for being a fellow for free knowledge and open science (Fellow-Programm Freies Wissen), which is sponsored by Wikimedia Foundation. The program includes some money as well as mentoring and opportunities to network with other people, which are enthusiastic about open science.

Due to corona, the event was online. The first day we had a nice presentation with Judith Simon about ethics in computer science and especially in artificial intelligence and machine learning. The second day was all about our projects. We talked to our mentors and the people from Wikimedia gave us an overview over the program and open science in general

You can find my project at the project page. It will be about improving our project Schularchive (school archives). Our focus is three-fold:

  1. We want to promote the platform more to attract more users within the research community history of education as well as archivists at schools.
  2. We want to improve the platform using feedback of users.
  3. We want to dive deeper into the question how data stored at our wiki can be connected with wikidata and ultimately, which data should be in our wiki and which data should be in wikidata

If you want to connect or use the platform for your teaching, contact us via the platform or via or Twitter account: @Schularchive.

We also did a little networking and other fellows recommended interesting pages I want to share:


Virtual Open Sym 2020

Open Sym this year was held online. My collegues from University of Washington, Seattle and me handed in a paper about an evaluation of the ontology I developed during my phd. The conference was organized in a different manner than last time. There were no parallel sessions and the presentations were rather short, abut ten minutes. Each session consisted of two to three presentations of the respective papers. Through this format, it was possible to get all presentations and the discussions were quite nice.

The social event was held via Mozilla Hubs. I think this was a good idea, but it is not the same as meeting with the people in person. It was also not that easy to have a real private talk within the virtual room, since everyone was able to hear what the others were talking about, although it got more quiet the further you were away from the people.

All in all, I think we should soon try to get back to face-to-face conferences. The discussions of the articles were rather interesting, but most of the time it is way more interesting to talk with people over a coffee or at a social event about stuff. All this was not possible. On the other side, we might use corona to think if it is necessary to conferences at the most exotic places attract people, or rather on less exotic places and save travel costs and time.