Abstract: Consistent measuring and reporting of gaze data quality is important in research that involves eye trackers. We have developed TraQuMe: a generic system to evaluate the gaze data quality. The quality measurement is fast and the interpretation of the results is aided by graphical output. Numeric data is saved for reporting of aggregate metrics for the whole experiment. We tested TraQuMe in the context of a novel hidden calibration procedure that we developed to aid in experiments where participants should not know that their gaze is being tracked. The quality of tracking data after the hidden calibration procedure was very close to that obtained with the Tobii's T60 trackers built-in 2 point, 5 point and 9 point calibrations.