@conference {LibKor-RMDEA-2013, title = {The Role of Metadata in the Design of Educational Activities}, booktitle = {Proceedings of CERME 8, Antalya}, year = {2013}, keywords = {refereed}, author = {Paul Libbrecht and Ulrich Kortenkamp} } @conference {LibKorRebMul-TCTA-2013, title = {Tales of a Companion Teacher Analytics}, booktitle = {Proceedings of the 2nd International Workshop on Teaching Analytics (IWTA-2013)}, year = {2013}, keywords = {refereed}, url = {http://ceur-ws.org/Vol-985/paper4.pdf}, author = {Paul Libbrecht and Ulrich Kortenkamp and Sandra Rebholz and Wolfgang M{\"u}ller}, editor = {Ravi Vatrapu} } @booklet {TrgKorJahLibMerRecSou-IPSDGROE-2010, title = {I2Geo.net {\textendash} a platform for sharing dynamic geometry resources all over Europe}, year = {2011}, keywords = {poster}, author = {Trgalova, Jana and Kortenkamp, Ulrich and Jahn, Ana Paula and Libbrecht, Paul and Mercat, Christian and Recio, Tomas and Soury-Lavergne, Sophie} } @unpublished {LibKorMer-CCBWLTIGR-2010, title = {Crossing Cultural Boundaries with Long Term Interactive Geometry Resources}, year = {2010}, note = {Unpublished Manuscript}, keywords = {sonstige}, author = {Libbrecht, Paul and Kortenkamp, Ulrich and Mercat, Christian} } @conference {AbaBotEscHenKorKreLibMarMer-IFFP-2009, title = {The {I}ntergeo File Format in Progress}, booktitle = {Proceedings of the 22nd OpenMath Meeting}, year = {2009}, abstract = {In this paper we describe the ongoing effort to specify a com- mon file format for Interactive or Dynamic Geometry Systems (DGS). Our approach is based on the OpenMath standard, and uses its flexible extension mechanisms like Content Dictionaries. We discuss the various design decisions, the Content Dictionaries that have been defined, as well as open questions to be resolved.}, keywords = {Intergeo, refereed}, author = {Ab{\'a}nades, Miguel and Botana, Francisco and Escribano, Jes{\'u}s and Hendriks, Maxim and Kortenkamp, Ulrich and Kreis, Yves and Libbrecht, Paul and Marques, Daniel and Mercat, Christian} } @conference {AbaBotEscHenKorKreLibMarMer-IFFP-2009, title = {The {I}ntergeo File Format in Progress}, booktitle = {Proceedings of the 22nd OpenMath Meeting}, year = {2009}, abstract = {

In this paper we describe the ongoing effort to specify a com- mon file format for Interactive or Dynamic Geometry Systems (DGS). Our approach is based on the OpenMath standard, and uses its flexible extension mechanisms like Content Dictionaries. We discuss the various design decisions, the Content Dictionaries that have been defined, as well as open questions to be resolved.

}, keywords = {refereed}, author = {Ab{\'a}nades, Miguel and Botana, Francisco and Escribano, Jes{\'u}s and Hendriks, Maxim and Kortenkamp, Ulrich and Kreis, Yves and Libbrecht, Paul and Marques, Daniel and Mercat, Christian} } @conference {LibKorMer-IWIG-2009, title = {I2Geo: a Web-Library of Interactive Geometry}, booktitle = {Proceedings of the 2nd Workshop Towards a Digital Mathematics Library (DML-2009)}, year = {2009}, publisher = {Masaryk University}, organization = {Masaryk University}, keywords = {refereed}, isbn = {978-80-210-4781-5}, author = {Paul Libbrecht and Ulrich Kortenkamp and Christian Mercat}, editor = {Petr Sojka} } @conference {KorBleDohKreLibMer-IIGEFTERFCIP-2009, title = {Interoperable Interactive Geometry For Europe {\textendash} First Technological and Educational Results and Future Challenges of the Intergeo Project}, booktitle = {Proceedings of the Sixth Congress of the European Society for Research in Mathematics Education. January 28th - February 1st 2009, Lyon (France)}, year = {2009}, month = {January}, publisher = {Proceedings of the Sixth Congress of the European Society for Research in Mathematics Education}, organization = {Proceedings of the Sixth Congress of the European Society for Research in Mathematics Education}, address = {Lyon (France)}, abstract = {In this overview article we describe the manifold achievements and challenges of Intergeo, a project co-funded within the eContentplus programme2 of the European Union.}, keywords = {Intergeo, refereed}, url = {http://www.inrp.fr/publications/edition-electronique/cerme6/wg7-11-kortenkamp.pdf}, author = {Kortenkamp, Ulrich and Blessing, Axel M. and Dohrmann, Christian and Kreis, Yves and Libbrecht, Paul and Mercat, Christian} } @conference {KorBleDohKreLibMer-IIGEFTERFCIP-2009, title = {Interoperable Interactive Geometry For Europe {\textendash} First Technological and Educational Results and Future Challenges of the Intergeo Project}, booktitle = {Proceedings of the Sixth Congress of the European Society for Research in Mathematics Education. January 28th - February 1st 2009, Lyon (France)}, year = {2009}, month = {January}, publisher = {Proceedings of the Sixth Congress of the European Society for Research in Mathematics Education}, organization = {Proceedings of the Sixth Congress of the European Society for Research in Mathematics Education}, address = {Lyon (France)}, abstract = {

In this overview article we describe the manifold achievements and challenges of Intergeo, a project co-funded within the eContentplus programme2 of the European Union.

}, keywords = {refereed}, url = {http://www.inrp.fr/publications/edition-electronique/cerme6/wg7-11-kortenkamp.pdf}, author = {Kortenkamp, Ulrich and Blessing, Axel M. and Dohrmann, Christian and Kreis, Yves and Libbrecht, Paul and Mercat, Christian} } @conference {KorMat-PIGC-2004, title = {Pen-based input of geometric constructions}, booktitle = {Proceedings of MathUI 2004}, year = {2004}, abstract = {

Pen-based input is the classical approach to drawing. Without computers, using a pen was the natural approach to do drawings, and the simplicity of this "device" always called for similar electronic solutions. Today, a broad range of electronic input devices is available that try to pair the simplicity of input with the power of computing. They come in all sizes: from small touch-screens with stylus in personal digital assistants, via desktop-size input tablets or interactive displays, to electronic whiteboards with rear- or front-projection. These devices all share a direct interaction paradigm. The challenge in using these devices for geometric constructions is to automatically annotate the drawn objects with their relations to the other objects. A basic example is the drawing of a right-angled triangle: How can we automatically recognize the user{\textquoteright}s intention to have a right angle? Can we do that at all? Do we really want to do that? If not {\textendash} what is the easiest pen-compatible way to have the user add this information? We will demonstrate several approaches to these problems, implemented in a development version of Cinderella. Another interesting issue is the presentation of hand-drawn figures: Is it possible to preserve the look of a sketch while still guaranteeing mathematically correct figures? Using the additional information gathered by automatic theorem proving we show some solutions.

}, keywords = {refereed}, url = {http://kortenkamps.net/papers/2004/Scribbling-article.pdf}, author = {Kortenkamp, Ulrich and Materlik, Dirk}, editor = {Libbrecht, Paul} } @conference {KorRic-UATPIUGS-2004, title = {Using Automatic Theorem Proving to Improve the Usability of Geometry Software}, booktitle = {Proceedings of MathUI 2004}, year = {2004}, abstract = {

Dynamic or interactive Geometry software (DGS) is the mathematical version of vector based drawing software: the objects (points, lines, circles, conics, polygons, etc.) are both graphical and mathematical entities. This allows adding relations between the objects that govern their behavior. Thus, DGS is used as an input tool for constructions, as opposed to simple drawings. The additional information that is present in a construction can be used to greatly enhance the usability of DGS. We show how automatic theorem proving can be used to remove redundant elements in a construction that obstruct a smooth work flow clarify the semantics of user actions, and improve the graphical rendering of elements. Finally we discuss the various possibilities of transforming the mathematical tool DGS into an educational tool. Here, automatic theorem proving is used to analyze user actions and to react properly.

}, keywords = {refereed}, url = {http://kortenkamps.net/papers/2004/ATP-UI-article.pdf}, author = {Kortenkamp, Ulrich and Richter-Gebert, J{\"u}rgen}, editor = {Libbrecht, Paul} }