Figure 2

Timeline of the absolute prediction errors of final polls and data fusion methods. The bars on the left side of the timeline represent the prediction errors of the data fusion methods. In each interval between two gray dashed lines, there are two bars. The lower bar represents the absolute error of the online data fusion method, and the upper bar represents the absolute error of the online–offline data fusion method. The interval between two gray horizontal dashed lines indicates one day. The bars on the right side of the timeline show the prediction errors of the final polls from ten pollsters. Comparison of the bars on both sides shows that the absolute prediction errors of the signal fusion methods are smaller than those of the polls