Examples of Increasing and Decreasing Bias

Each curve shows performance of different versions of one company’s model. The companies are Sensetime and Rank One Computing (ROC). The dashed black line at the bottom of the chart shows a ratio of 1, indicating no bias. The horizontal axis indicates the number of months since the first model was tested by NIST. For example, the solid red line shows that Sensetime’s performance has become somewhat more biased over time, measuring the ratio of errors between West African and Eastern European faces.