Graph Transformation Day Bremen

Directly after the World Usability Day in Dresden I attended the Graph Transformation Day in Bremen. Here, I gave a talk about the generation of correctness-preserving editing operations for diagram editors. More on this later...

The other talks have been given by my supervisor Prof. Mark Minas (about using triple graph grammars for analysis in diagram editors), Dr. Rubino Geiß, the architect of the GrGen graph transformation engine (and indeed his talk was about the implementation and application of GrGen), and finally Edgar Jakumeit, who described the realization of recursive matching rules for GrGen. I have found these recursive "star" rules particularly interesting, because they actually allow to write parsers with GrGen in a declarative style. In a sense, this is quite similar to my approach to graph parsing via combinators.

It was a nice workshop. I learned a lot about the GrGen system. In particular I now have an idea how they managed to build the fastest (at least in quite some cases) graph transformation tool in the wild. Thank you Berthold for organizing this...

World Usability Day Dresden

Last Thursday I gave a talk at the World Usability Day Dresden with the title "Nutzerunterstützung in Diagramm-Editoren zum Erlernen visueller Sprachen" (in English: User assistance for diagram editors supports the learning of visual languages). I provide an abstract of my talk (in German) on my website. I got quite encouraging feedback and some nice tips on how to actually conduct a user study.

All in all, I really liked this workshop. It was well organized by Jan-Henning Raff from the media center of TU Dresden. There have been round about 50 participants listening to the ten talks. Although I am not a usability expert (I just start exploring this domain), I learned a lot from most of the talks. In particular I enjoyed the talks about tools:

• Jürgen Steimle introduced the CoScribe-System, an impressive pen-and-paper-interface for collaboration based on the Anoto approach.


• Stefan Meißner from seto company talked about Enterprise 2.0 and introduced a nice WYSIWYG editor for websites.


• Severin Taranko from queo media demonstrated a WordPress plugin that gives visitors of your blog an overview over the most relevant and popular articles of your blog (using some reasonable criteria).


• Robert Jung motivated the use of sketch tools for CAD. In particular he showed a nice video of a tool developed at the university of Toronto: ILoveSketch. There is a nice video on the tool's website.


• Prof. Gerhard Weber and one of his students talked about accessibility in (web) applications. They have improved the accessibility of the Moodle learning platform for blind people. Furthermore, they have studied how blind and non-blind people collaborate in the creation of UML class diagrams.

The day was completed by a "Usa-beer" evening in a nice bar of Dresden.