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Homepage of Kai-Uwe Carstensen

Information about Kai-Uwe Carstensen

picture of kai
I am a language-oriented cognitive scientist. That means, I am working in the interdisciplinary field of linguistics, computational linguistics, artificial intelligence and psychology (plus some more) which constitutes cognitive science. In other words, I am interested in how language relates to the world via cognitive representations and psychological processes.

I am one of the few who believe, and for more than 20 years now say, that selective attention plays an important role in cognition, much more important than currently acknowledged.

“The problem of understanding the relation between concepts and perception is about as fundamental as any which we currently face, and the key to it is provided by the notion of selective attention.”
John Campbell

Besides these theoretical concerns, I have always had a great interest in the practical applications of computational linguistics (language technology, or Sprachtechnologie in German).

Ideally, both lines of interest meet when understanding how language functions helps to make better applications. This, actually, seems to be corroborated be recent developments:

“A recent trend in Deep Learning are Attention Mechanisms. [...] Ilya Sutskever, now the research director of OpenAI, mentioned that Attention Mechanisms are one of the most exciting advancements, and that they are here to stay.”
Denny Britz

Think what you want, but try to think different.

“Here's to the crazy ones. The misfits. The rebels. The troublemakers. The round pegs in the square holes. The ones who see things differently. They're not fond of rules. And they have no respect for the status quo. You can quote them, disagree with them, glorify or vilify them. But the only thing you can't do is ignore them. Because they change things. They push the human race forward. And while some may see them as the crazy ones, we see genius. Because the people who are crazy enough to think they can change the world, are the ones who do.” (from: Wikipedia, Think_Different)

C. V.

  • studies of Linguistics and Computer Science at the universities of Trier and Hamburg with a focus on Computational Linguistics and language oriented AI.
  • Magister Artium (M.A.) in 1991 with a thesis on the cognitive aspects and the automatic generation of route descriptions
  • since then researcher and lecturer at
    • the Institute of Semantic Information Processing / Cognitive Science (and the 'Computational Linguistics and AI' department) at the University of Osnabrück
    • the Institute for Computational Linguistics (IMS) at the University of Stuttgart
    • the Institute of Computational Linguistics at the University of Zurich, Switzerland
    • the Institute of Linguistics and Computational Linguistics at the University of Bochum
    • the Philosophical faculty at the University of Siegen
  • Dr.phil. in 1998 with a doctoral thesis on 'Language, Space, and Attention'
  • Vertretung der Computerlinguistik-Professur an der Uni Freiburg/Breisgau (Ex- Udo Hahn) (4/2005-3/2007)



You can contact me via Email: "contact" at ""



Research interests

The general fields of my interest are language oriented Cognitive Science and Computational Linguistics.

Specific fields of interest:

  • Spatial and temporal knowledge representation and processing
  • Role of attention within cognitive systems and for language
  • Language understanding and generation.
  • Linguistic text classification
  • Cognitive, computational semantics
Specific interests:
  • Spatial object knowledge (representation)
  • Spatial relations
  • (Micro)Perspectivization
  • Gradation phenomena
  • Generation of complex discourse types (e.g., route descriptions)
  • Inferring discourse relations from temporal information given in texts
  • Teaching Computational Linguistics. Special interest in problem-based interactive learning applications
  • Computer-aided summarization of texts
  • Language technology, in general
  • Quantification, compositionality, and underspecification
  • Ontologies

Currently, I am interested in Cognitivist attentional semantics.

Publications of Kai-Uwe Carstensen

Here's the list of publications as pdf.


LILOG (1987-1991)

This was a basic research project in which a system for understanding texts was developped (for a survey, see "Text Understanding in LILOG").

Interestingly, I added a component for generating route descriptions to the system (see the following figure). I did this work as a student of Computational Linguistics and Artificial Intelligence in the subproject LILOG-SPACE at the University of Hamburg.

Wegbeschreibungen Carstensen
(from: Brenner, Robert (1990), IBM als Partner der Wissenschaft, IBM Forum D12-0035.)


OSKAR (1989-1990)

OSKAR was a small PROLOG-based prototype I developped for testing and extending Ewald Langs cognitive-semantic theory of dimensional adjectives. It is based on spatial conceptual object schemata as representations of qualitative spatial information. These object schemata are used in OSKAR to determine whether specific combinations of dimensional expressions and object names can be conceptually interpreted (for example, "high hill" and "deep valley" are meaningful expressions, while "deep hill" and "high valley" are not).


SPACENET (1994 - 1998)

SPACENET was an EU funded Human Capital Mobility Network that brought together the eleven major European spatial reasoning groups (see the main SPACENET-page for more information). The project investigated qualitative aspects of spatial representation and reasoning.
I was participating as a member of Christian Freksa's group at the University of Hamburg.




GROBI was an extension of OSKAR which I developped for my dissertation thesis "Sprache, Raum, und Aufmerksamkeit [Language, Space, and Attention]". In addition to object aspects, it took into account relations between objects, the qualitative designation of distances, and aspects of gradation (e.g., "x is less than 2 metres higher (above y) than..."). GROBI thus presented an answer to some problems of the combinatorics of distance and relation expressions occurring at least in German (compare also "a few metres behind the house" and ?"a few metres close to the house"), which I investigated in my thesis.

The theoretical core of the thesis is that changes of (spatial) attention are necessary for the construction of conceptual spatial relations, which has to be reflected in the semantics of corresponding spatial terms. Here you can find the part (written in German) introducing aspects of spatial attention (see also the bibliography of the thesis).

There are other researchers interested in the role of attention in cognition and on attentional semantics, some of which are listed on a website maintained by Giorgio Marchetti (or go directly to his website of the book Attention and Meaning. The Attentional Basis of Meaning).


GERHARD I (10/1996 - 3/98)

The GERHARD-project (German Harvest Automated Retrieval and Directory) aimed at classifying texts on the web and their later retrieval according to topic-oriented queries. In this project, we used the Universal Decimal Classification (UDC) of the ETH Zürich to map natural language texts onto categories of the UDC-hierarchy.


Here´s a quote from c't magazin (13/98)

GERHARD kann jedoch noch mehr: es ist derzeit die einzige Suchmaschine weltweit, die aus den Dokumenten automatisch einen nach Themengebieten geordneten Katalog erzeugt. Das Programm analysiert den Volltext und kategorisiert die Dokumente nach der dreisprachigen universalen Dezimalklassifikation der ETH Zürich (UDK). Das UDK-Lexikon enthält zur Zeit rund 70 000 Einträge.

There was a small follow-up project GERHARD II.


International Bachelor-Master-Programme Cognitive Science (-9/99)


Cognitive Science Perspektiven

Since the winter semester 1998/1999, a new international Bachelor-Master-Programme Cognitive Science has been established at the University of Osnabrück. In this context, I worked as an official coordinator.

Here´s a picture I created, intended to demonstrate the perspectives (taken literally) of the then quite young discipline:

that unravelling (aspects of) the brain will shed light on aspects of the mind (-body problem).

I used this poster in talks given - among others - in Athens, Hongkong, and Warschau.


Computational Semantics (-12/2000)

This was a project in the group of Hans Kamp at the IMS (Institut für Maschinelle Sprachverarbeitung (Institute for Natural Language Processing)), Stuttgart, of which I was a member in the final year.

What I did was some kind of 'proof-of-concept' implementation of discourse interpretation theories in the context of segmented underspecified discourse representation structures, including some use of constraint logic programming for solving temporal constraint problems.

Have a look at the quite ambitious original project goal.


WebCL: Web-based problem-based teaching and tutoring of introductory Computational Linguistics courses

In this project at the University of Zurich, we combined enhanced traditional, but electronic, lecture notes, Web-based computer aided learning and the idea of Problem-based learning to yield a new approach, TIP (for 'Text-centred concept for Individual learning featuring Problem-based interactive learning applications'), aimed at supporting introductory Computational Linguistics courses.

Have a look at the volume of Linguistik online on "Learning and teaching (in) Computational Linguistics" I have edited.


Computer-aided summarization of text (CAST)

This was a small prototype I developed in Python for MacOSX (with PyObjC). Intended to provide several adjustable filters with an additional one-click facility to add/delete a clause to/from the summary.


Computerunterstützte Textzusammenfassung


Dialektatlas Mittleres Westdeutschland (DMW)

In this 17+-year long (2016-) project financed by the Academy of Sciences of Northrhine-Westfalia, we collect spoken dialect data in and around Northrhine-Westfalia and analyze them wrt. a set of phenomena (roughly, 3000+ speakers at 800+ places; 800+ verbal tasks each; often more than one phenomenon per task), all stored in a database. The latter will be accessed by web interfaces that will dynamically generate geo-referenced maps with spoken items according to some query.

As a computational linguist, I coordinate the information flow between the informatics department and the linguists at the participating universities (Bonn, Münster, Paderborn, Siegen) (website).


Cognitivist Ontologies (CogOnt)

Here I am investigating cognitively motivated upper ontologies (Carstensen 2011 Paper). Theoretically, they are needed as a missing link between realist and conceptualist ontologies. Practically, they are assumed to be relevant at least for language technology applications.

On that basis, an attention-based cognitivist semantics of linguistic expressions (gradation expressions, Carstensen 2013 Paper; locative prepositions, Carstensen 2015, in a Pdf of the whole book) can be specified.

Some have asked me why I use the term Cognitivist so prominently and often. The answer has two parts. First, there is a certain general connection: Recently, I found a proposal from 1998 (not written by me) for a 'Meaning and cognition' research group on my hard drive. It suggests a non-specific interpretation:

It will be convenient to have a name for the general approach outlined above; we will refer to it as the 'cognitivist' approach, because we believe that the essential trait that most recent semantic theories have in common is that they share a broadly cognitivist outlook. 'Cognitivist semantics', as we use the term, denotes neither a school, nor even a set of premises shared by a given range of theories. The term is merely to suggest a certain trend in semantic theory which we endorse, and which stands in marked contrast to the views underlying most philosophical approaches to semantics.
Yet it is already connected to me, as one branch of relevant theories was referred to as follows (in which the publication of my dissertation thesis was still forthcoming)(my emphasis):
Semantic theories developed within the framework of cognitive linguistics such as Jackendoff (1983), Herskovits (1986), Lakoff (1987), Habel (1988), Habel, Kanngießer, and Rickheit (1996), and Carstensen (forthcoming). The work of Bierwisch and his associates may be seen as part of these developments, too (Bierwisch 1983, Bierwisch and Lang 1987).
The second part of the answer is that since 2011, I use this term non-generically to refer to my attentional approach to semantics and ontology, different aspects of which are addressed in my recent papers. Accordingly, Cognitivism not only refers to a cognitive position, but more specifically to an alternative theoretical stance on ontology (as opposed to, e.g., Conceptualism and Realism), based on recent insights gained in Cognitive Science.

I am also working on adapted logics that are based on cognitivist ontologies and usable for cognitivist semantics. If you're interested, read the Draft of my paper about why we need a different predicate logic.


Sprachtechnologie / language technology

Co-Editing the German Introduction to Computational Linguistics and Language Technology (Computerlinguistik und Sprachtechnologie - eine Einführung)

Click on a picture to get to the homepage of the respective edition.

Titelbild Einfuehrung Computerlinguistik und Sprachtechnologie, 1. Auflage Titelbild Einfuehrung Computerlinguistik und Sprachtechnologie, 2. Auflage Titelbild Einfuehrung Computerlinguistik und Sprachtechnologie, 3. Auflage

I was also reviewer of the German handbook of Artificial Intelligence ("Handbuch der Künstlichen Intelligenz") (for the natural language processing part), and was one of the many mentioned in the preface of the world's most prominent introduction to speech and language processing by Dan Jurafsky and James Martin (2nd ed.).

Language Technology - A survey (Sprachtechnologie - ein Überblick)

Titelbild Sprachtechnologie Carstensen

Based on my lectures on Natural Language Systems and Language Technology, I have written a small online-book in German on the main applications/system types of computational linguistics.

Click on the fake picture to download a pdf.

Über Anmerkungen/Feedback würde ich mich freuen.




  • My extensive German review of the German version of Sebastian Löbner's Understanding Semantics (Semantik - Eine Einführung), 2nd. ext. ed., has appeared (Carstensen, Kai-Uwe (2017): Rezension von "Löbner, Sebastian (2015): Semantik: Eine Einführung. 2., aktualisierte und stark erweiterte Auflage. Berlin/Boston: DeGruyter", Linguistische Berichte 250, 247-262).
  • I have learned a lot about reviewing over the years. To share this knowledge, I have compiled a set of rules for reviewing (caution: satire). Feel free to distribute! There'll be more soon.
  • Here's A Personal View on Reviewing now. Have fun reading! Comments are welcome!
  • Here's the abstract of my talk at the conference "Visualisierungsprozesse in den Humanities" (VisuHu 2017), at the university of Zurich, Switzerland.
  • Just back from the conference "Language and Perception" at the university of Berne, Switzerland.
    Here are the slides of my talk on Cognitivist attention-based semantics of directionals.

This page

In case you didn't know: I love contrasts. Sea (where I come from) vs. mountains (where I lived for a while) is one of them. The picture of the mountains (Eiger, Mönch, Jungfrau) was taken by me only a few kilometres away from the place where I lived.
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