Local.PD.Linkage.Definition.Individual Explanation

Can someone give me an explanation of how Local.PD.Linkage.Definition.Individual works? This was setup by another company as part of our implementation.

Below is my configuration..

We are getting a lot of matches on Given Name, but then the Family Name does not match at all, so I am wondering if these need to be adjusted. I just don't understand if they need to be positive or negative.

if I use the MLE CALIBRATION MONITOR, it seems that none of the values should be negative.