Prof Jürg Kohlas
 Professor emeritus of Theoretical Computer Science
Research Interests
Algebraic Theory of Information
Information is related to questions, it must be focused on the questions of interest, and it comes often in different pieces, or from different sources and must aggregated. This can be captured in twosorted algebras, linking elements representing pieces of information and elements representing distinct questions. In this research project, these algebras are studied based on different, but related axiomatic bases. These algebras allow for generic distributed local computation schemes. Different computational architectures are developed and implemented. Further representations of information based either on universal logic systems or on general relational systems are studied. Finally, uncertain information is modeled by random variables taking values in information algebras.
most recent research:
Algebras of Information. A New and Extended Axiomatic Foundation
Probabilistic Argumentation
Often information depends on uncertain assumptions. Hypotheses may then be deduced or proved assuming certain of these assumptions. By considering the likelihood or probability of the assumptions involved, the reliability with which the hypotheses can be deduced or proved can be computed. This defines degrees of support for the hypotheses. These degrees form belief functions in the sense of DempsterShafer theory of evidence. These probabilistic argumentation systems link logic and probability for inference in a very natural way going back to the founder of stochastics, J. Bernoulli. Computational architectures for probabilistic argumentation systems have been implemented in the framework of propositional logic. Further, in the abstract setting of information algebras they are induced by random variables with value in information algebras. In this direction the project is pursued under the first heading.
Other Work
History of Computing
Other Activities

Painting (see here)
Further Activities
 Former member of the council of Hasler Foundation.
Recent Publications
Uptodate:
 Interview in The Reasoner. Volume 2, Number 1, 2008.
Books:
A Mathematical Theory of Hints
Statistical Information: AssumptionBased Statistical Inference
Coeditor of:
Dependable Sysstems: Software, Computing, Networks
Recent Papers:
 Uncertain Information: Random Variables in Graded Semilattices
 Information Algebras and Consequence Operators
 An Algebraic Theory for Statistical Information based on the Theory of Hints
 Generic Local Computation
 Generalized Information Theory for Hints
 An Algebraic Theory of Information: An Introduction and Survey
 On Conditions for Semirings to Induce Compact Information Algebras
 Inverses, Conditionals and Compositional Operators in Separative Valuation Algebras
 Algebras of Information. New and Extendced Algebraic Foundations
 Information and Set Algebras: Interpretation and Uniqueness of Conditional Independence
Further Papers:
See my publication list here.
New: Computer Science in School:
The German version is out of print. It is however available as ebook, see here
Alternatively it can be downloaded here
Press Articles on Computer Science in School:
La Liberté: L'informatique en branche principale
La Liberté: Urgent: Cherche informaticiens
Sonntagszeitung: Kosten sparen
La Liberté: La science informatique pourrait devenir une branche principale
L'HEBDO: Sus à l'analphabétisme informatique
Freiburger Nachrichten: Um die neue Welt besser verstehen zu können
Contact
Kohlas Jürg Department of Informatics Boulevard de Pérolles 90 1700 FRIBOURG (Switzerland) 
office : PER 2, C409 phone : +41 26 300 8338 email : juerg.kohlas@unifr.ch 