What is Equal Error Rate and Why Should You Care?
Equal Error Rate (EER) is a metric that balances the False Acceptance Rate (FAR) and the False Rejection Rate (FRR). It helps you assess how well a security system is performing.
If you're managing security systems, like biometric scanners or electronic access controls, you should be interested in EER. It provides a single standardized measure to evaluate the trade-off between incorrectly allowing unauthorized users and wrongly rejecting authorized ones. In other words, EER helps you determine if your system is secure but also user-friendly.
How to Calculate Equal Error Rate
The formula to calculate Equal Error Rate is:
[\text{EER} = \frac{\text{FAR} + \text{FRR}}{2}]
Where:
- False Acceptance Rate (FAR) is the measure of unauthorized access accepted by the system
- False Rejection Rate (FRR) is the measure of the system rejecting authorized access attempts
Calculation Example
Imagine you have a security system with the following statistics:
- False Acceptance Rate (FAR): 8,500
- False Rejection Rate (FRR): 1,500
Using our formula:
[\text{EER} = \frac{8,500 + 1,500}{2} = \frac{10,000}{2} = 5,000]
So, in this case, the Equal Error Rate is 5,000. This number tells you that, on average, your security system is both falsely accepting and falsely rejecting access attempts at a combined rate of 5,000 per certain number of attempts.
In just a few steps, you've determined the EER for your system, helping you balance security and usability. That's the beauty of Equal Error Rate - it simplifies the complex trade-offs between security and convenience into one easy-to-understand metric.