Abstract-To evaluate multi-target video tracking results, one needs to quantify the accuracy of the estimated target-size and the cardinality error as well as measure the frequency of occurrence of ID changes. In this paper we survey existing multi-target tracking performance scores and, after discussing their limitations, we propose three parameter-independent measures for evaluating multi-target video tracking. The measures take into account target-size variations, combine accuracy and cardinality errors, quantify long-term tracking accuracy at different accuracy levels, and evaluate ID changes relative to the duration of the track in which they occur. We conduct an extensive experimental validation of the proposed measures by comparing them with existing ones and by evaluating four state-of-the-art trackers on challenging real-world publicly-available datasets. The software implementing the proposed measures is made available online to facilitate their use by the research community.