We describe a series of experiments that compared 2D/3D input methods for selection and positioning tasks related to medical image analysis. For our study, we chose a switchable P5 Glove Controller, which can be used to provide both 2DOF and 6DOF input control. Our results suggest that for both tasks the overall performance and accuracy can be improved when the input device with more degrees of freedom (DOF) is used for manipulation of the visualized medical data. 3D input turned out to be more beneficial for the positioning task than for the selection task. In order to determine a potential source of the difference in the task completion time between 2D and 3D input, we also investigated whether there was a significant difference between 2DOF and 6DOF input methods with regard to the time spent on task-specific basic manipulations.