Methods, apparatus, and systems for monitoring a technician's performance of a marking operation to indicate the presence or absence of an underground facility, wherein the technician uses a marking device. Operating information representative of motion of the marking device during performance of the marking operation by the technician is analyzed to determine a pattern of motion. In one example, the pattern of motion is compared to at least one previously-identified pattern of motion associated with at least one technician. In various aspects, the operating information may representative of an acceleration, a velocity, a distance traveled by, and/or an angle of inclination of the marking device. In another aspect, the previously-identified pattern of motion may be a technician signature representing a pattern of motion unique to a technician.