Which is more important? Accuracy or Acceptability?


Which criteria is the most important consideration for the selection and deployment of a biometric authentication system?
A. Crossover error rate (CER) or Equal error rate (ERR)
B. processing speed

I’m a little bit confused

Shon Harris 5th e

This question is a post from Ehab Badawi in Luke’s SNT group on 2019/05/04 6:59 AM Taipei Standard Time.

It seems to be a simple question at first glance. However, I would prefer B to A. It deserves more attention to think about the criteria for the selection and deployment of a biometric authentication system.

The accuracy of a biometric system can be evaluated by using well-known performance indicators, e.g., False Accept Rate (FAR), False Reject Rate (FRR), and Equal Error Rate (EER).

The value of the EER can be easily obtained from the ROC (relative operating characteristic) curve. The EER is a quick way to compare the accuracy of devices with different ROC curves. In general, the device with the lowest EER is the most accurate.

Based on the information above, EER or accuracy is an essential factor to consider when selecting a biometric authentication system.

However, when evaluating a biometric authentication system, there are other factors to consider, such as cost, acceptability, and so forth. Processing speed affects acceptability. Let’s consider the following case:

  • System A, EER=0.2, Processing speed=20,000 matches/sec
  • System B, EER=0.2, Processing speed=18,000 matches/sec
  • System C, EER=0.3, Processing speed=15,000 matches/sec
  • System D, EER=0.4, Processing speed=20,000 matches/sec

If our criteria to purchase a biometric authentication system is EER < 0.3 and Processing speed >= 15000. System A and B are the qualified alternatives. In general, we will select and deploy System A as it has a higher processing speed. In this case, the processing speed would be more decisive or more important.

So, which one is the most important consideration? EER or processing speed? And what does “important” mean? Undoubtedly, we have to take both of them into account to select and deploy a biometric authentication system.

I would treat EER as a selection criterion while processing speed the deployment criterion. EER depends on use cases, security first or convenience first; processing speed affects system throughput and user acceptability. In practice, I would prefer to choosing a system with higher processing speed from alternative systems with similar or equal EER. That’s why I prefer B to A, even though it seems that Answer A, CER or ER, is a more popular answer.




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