The paper introduces two new metrics, Multiple Object Tracking Precision (MOTP) and Multiple Object Tracking Accuracy (MOTA), to evaluate the performance of multiple object trackers. These metrics are designed to assess the precision in estimating object locations, the accuracy in recognizing object configurations, and the ability to consistently label objects over time. The metrics were tested in two large-scale international evaluations, the 2006 and 2007 CLEAR evaluations, which featured a variety of tracking tasks, including visual 3D person tracking, 2D face tracking, 2D person and vehicle tracking, and acoustic speaker tracking. The results demonstrate that the proposed metrics effectively reflect the strengths and weaknesses of different systems, allow for easy comparison of overall performance, and are applicable to a wide range of scenarios. The paper also discusses the advantages and drawbacks of the metrics based on the experience gained during the evaluations.The paper introduces two new metrics, Multiple Object Tracking Precision (MOTP) and Multiple Object Tracking Accuracy (MOTA), to evaluate the performance of multiple object trackers. These metrics are designed to assess the precision in estimating object locations, the accuracy in recognizing object configurations, and the ability to consistently label objects over time. The metrics were tested in two large-scale international evaluations, the 2006 and 2007 CLEAR evaluations, which featured a variety of tracking tasks, including visual 3D person tracking, 2D face tracking, 2D person and vehicle tracking, and acoustic speaker tracking. The results demonstrate that the proposed metrics effectively reflect the strengths and weaknesses of different systems, allow for easy comparison of overall performance, and are applicable to a wide range of scenarios. The paper also discusses the advantages and drawbacks of the metrics based on the experience gained during the evaluations.