Frequently Asked Questions¶

How do I interpret the returned score?¶

The score relates to the expected False Match Rate, which is the rate at which a random probe incorrectly matches against the wrong person. If you set the score threshold of your system to S, your expected False Match Rate follows this formula:

$1/(10^S)=False Match Rate$

So a score threshold of 1 means 10% FMR, 2 means 1% FMR, 3 means .1% FMR and so on. So if you want an expected False Match Rate of .01%, you would use a score threshold of 4.0.

What score threshold should I use?¶

If you don’t have any explicit requirements, we recommend that you start with a score threshold of 4.0. This gives you an expected False Match Rate of .01% or 1 in 10,000.