Equal Error Rate

A metric used to evaluate biometric system performance, representing the point at which the false acceptance rate (wrongly accepting unauthorized users) equals the false rejection rate (wrongly rejecting authorized users). Lower EER values indicate better system accuracy. In accessibility research, EER is used to assess whether biometric systems perform equitably across different user populations—studies often find that systems have higher error rates for older adults, people with motor impairments, or users with certain physical characteristics, raising concerns about discriminatory technology design.