While hiking in the “Kemptener Wald” (Cambodunum Forest) in May 2015, we came upon a strange riddle. There was a tombstone with engravings on all four sides, written in gothic letters. There was a word looking like “Dekonomensgattin” and another one that seemed to say “Dekonomsgattin”. As you later see, this can’t be translated, but I’ll try it nevertheless: “wife of deconomist”. Strange word, we thought. Neither my wife nor I had heard of this word, so at home we started searching for it in the world wide web. We had some hits on the search machines. All of them led us to old books and to chronicles of died persons. But we did not find, what the heck this meant. Finally the enlightenment came over us: While we examined the fotos and some of the links more closely, we identified the upper case D to be an upper case O instead. The strongly decorated upper case letters of the gothic font had deluded us. They even had deluded the OCR (optical character recognition) software of the search engines.

oekonom-nicht-dekonomNow look at your own: Would you have identified this without any references? In one of the scanned books we found with the search engine, we had managed to find words with upper case Ds and Os, so we were able to compare and differentiate them.


So, finally our word “Dekonom” became the word “Oekonom” (economist) – and that’s a word we all know…

Lessons learnt? Only because you get some hits when searching the web for something doesn’t mean the information is not faulty.

More lessons learnt? Typography can be difficult. As a designer you should always be aware that using wrong typefaces or fonts can result in generating text that can hardly be read – not only for human beings.

XML Tools Plugin for Notepad++

For a class lecture on XML I searched for a free text editing tool supporting syntax highlighting for XML, check if XML is well-formed an perform validation (e.g. with DTD). After some research I found out that a plugin for Notepad++ called XMLTools. I was very lucky because I already use Notepad++ for years. The installation of the plugin was no problem and had all the functions I needed for the class. In the first lecture everything worked fine. We checked for well-formed XML, developed some CSS for viewing in the browser and finally started writing a first DTD for a XML file.
Suddenly the students had files which couldn’t be found by the plugin, when they tried to validate their XML. A popup appeared telling us that it was “Unable to load the DTD xyz.dtd”. I examined the files but couln’t find any errors. I searched the net, but although I found some (elder) questions on that error, I didn’t find an answer.
So I took the files home and did some further research (trial and error). First thought was that the coding of the files was wrong, but that didn’t make any change – same error message.
Finally, it was more than one source of error. This told me once again, that error messages often don’t describe what really was the error (and that there should be different error messages for different errors!).

  1. Every syntax error in the DTD causes the “Unable to load” error. This means, if only one bracket is missing, a wrong character or similar small errors is contained in the DTD, the popup is displayed and no validation is possible.
  2. The second source of error actually was the coding: UTF-8 coded DTD-files can’t be loaded by the plugin. We were only able to validate XML files with ANSI coded DTDs (without error!)

Doctoral thesis published

Finally it is done – my doctoral thesis has been published:

The dissertation called “Der Interaktionsprozess bei Tangible Interaction – Entwicklung und Analyse eines Interaktionsmodells – Richtlinien zur Verwendung beim Design” is avaliable in Verlag Dr. Hut, ISBN 978-3-8439-0836-8. It is only available in german by now.

Being a subarea of Human Computer Interaction, Tangible Interaction is a multidisciplinary area. Since the first prototypes of systems with interfaces that physically represent digital information in reality and therefor provide an easier way for manipulation, this field of application grew explosively.
New technologies allow sensors to become smaller and cheaper and monitors to become bigger. This means new possibilities for interaction between human and computer arise.
This work addresses the design of a generic model for the interaction process of Tangible Interaction.
By means of this model the process can be examined with respect to critical issues. These findings on the other hand give an approach to optimize the design of Tangible Interaction systems in providing especially focused design guidelines.

Hick’s Law

In the 50s William Hick (a British psychologist) examined the speed of perception and information processing. In his experiments he created tasks where the subjects had to select a specific information from a list of information. He measured the change of the time needed for a selection, when the list of information was reduced in size. [1]. The evaluations of the experiments resulted in a logarithmic curve. He approximated the curve with the following formula for the rate of gain of information:

Formula in MathML format (not all browsers support this by now):


Formula in PNG image format:

The entrophy H is derived from the sum of the probabilities (pi) of possible selections multiplied by a logarithmic value (where n is the number of choices). The logarithm of this suggests that human beings do not perform a linear search in lists.  We rather try to divide them into categories. This allows us to exclude half the possibilities at each step.

In HCI Hick’s law is used to compare different menu layouts in graphical user interfaces in order to determine which one is most effective.

[1]: William Edmund Hick. On the rate of gain of information. Quarterly Journal of Experimental Psychology, 4(1):1126, 1952.

Old Artist-Homepage

After several years I updated my homepage and decided to remove the design of my old artist homepage. As I liked the design, I loaded up an image where you can see how it looked like. Well, it looked nice but was not very easy to maintain if I wanted to add new images…
Here’s the old layout:

The old version of the page remains online until I decide to remove it… it is located here: Old artist pages

My Wife’s Felting Page

In 2007 my wife Inés and I  made a dream come true: participate to a medieval fair. Inés had gained much experience in felting, so she wantet to felt with children at the market. At castle Katzenstein (engl: cat stone) the spectaculum took place. We were overwhelmed by the mass of children that wanted to felt with us. We rarely had time to get something to eat or drink. But we had so much fun we decided to do that again.

For the presentation of the felt works of my wife I built a homepage. Inés felted some pieces especially for the design of the homepage. We should renew some part of the page. But for treasuring all those felted blooms, hats and bags the page perfectly serves our needs.

Here you can view the (german) page:

Flyer for the museum in Bad Buchau

This Flyer was designed for the museum in Bad Buchau, Germany, called “Federseemuseum”. Since 2008, the museum has an annual event about herbs. This year, my wife and I missed the event for the first time.


I like fonts. I really like fonts. Typography is a really interesting thing. With the right font you can emphasize the meaning of your text so heavily.

As my wife and I love nostalgic things, we often go to flea markets. Once we found a real treasure: An old, handwritten doctoral thesis. I like old handwriting and so I started to build a handwriting font.

18th Century Handwriting Font Example

You can see and download the font called handwriting1800 (TTF) at my deviantart stock account page, and many free font pages also have listed it by now (although the newest version can be found on my deviantart page always).

I hope you like it. If you use it, I would love to see what you did with it (send me an email or a note on deviantart).

Malleus Monstrorum

In 2008 Pegasus Press released the book Malleus Monstrorum 2nd Edition, a monsters compendium for Cthulhu role playing game. There are several works I did combining pencil drawings, ink drawings, photomanipulations and digital drawings. The images had to look like they were actually real findings of Cthulhu monsters in historic books, on ancient plates etc. The book is really worth a look, though it is only available in german language.