to grayscale in order to increase similarity to the segmentation process of medical images acquired from . The conversion is performed in accordance with the [](https://www.itu.int/rec/R-REC-BT.709/en) recommendation [@recommendation1990basic] for the extraction of true luminance defined by the International Commission on Illumination () from contemporary cathode ray tube () phosphors via are the linear red, green, and blue color channels respectively. $$\mathbf{I} = 0.2126 \cdot \mathbf{I}'_R + 0.7152 \cdot \mathbf{I}'_G + 0.0722 \cdot \mathbf{I}'_B     \label{eq:rgbtograyscale}$$ (b) is initially presented to the in order to familiarize themselves with the upcoming segmentation process. The segmentation tasks associated with images (a,c,d) are then displayed sequentially to the subjects in randomized order. The images are chosen to fulfill two goals of the study. (1) Ambiguity of the ground truth has to be minimized in order to suppress noise in the quantitative data. Each test person should have the same understanding and consent about the correct outline of the object to segment. Therefore, clinical images can only be utilized with groups of specialized domain experts. (2) The degree of complexity should vary between the images displayed to the users. Image (b), depicted in **Fig.**\[fig:study\_data\_sets\], of moderate complexity with regards to its disagreement coefficient [@hanneke2007bound], is displayed 