This book shows the implementation of a new innovative item type for the eAuthor computer-based testing system. Therefore, the provided interfaces of the eAuthor system had to be further analyzed. The so called graphical marking item type enables marking within a provided image to highlight a speci c area of interest. This marking, which can be performed using various forms of marking, will be compared and scored against a solution marking afterwards. The scoring will happen on the basis of two dimensional intersection areas, which had to be calculated and will be discussed in the theoretical chapter.