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.

Abstract
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.

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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):

$H=∑inpilog2(1pi+1)$

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.

Remark:
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):1126, 1952.