Abstract: In this paper we present the results of a user study comparing the readability of force-directed, orthogonal, and hierarchical graph layouts. To this end we identified prototypical tasks which are solved using visual representations of graphs. Based on the correctness of answers and the related response time we evaluated for each task which layout is better suited. In addition, we found possible explanations for these results by analyzing the eye-tracking data. Finally, we discuss some implications of our findings for algorithm designers and application developers.