Task sheet were fixed under the transparent overlay of a digitizing graphic tablet
which imitated the paper surface. Friction of that foil was comparable to the friction of normal paper
Performance was visualized on the screen in order to administer the tasks and to verify that they were carried out correctly. Participants were not able to see the screen and thus had no visual feedback. Position and pressure of the pen were detected with a sampling rate of 200 Hz and a spatial resolution of 0.05 mm. Measurements began automatically when the participant first touched the pen to the digitizing tablet