I just posted a link:
ABOUT MAGISTRATE JUDGES:
http://www.cand.uscourts.gov/filelibrary/34/MagistrateJudgeBrochure-7-2011.pdf

I urge you read it - it was written (in name) by Judge Ware and includes bios as well as this:

The Northern District is one of the few federal trial courts in the country to assign a wide range of civil cases directly to magistrate judges upon filing. As a consequence, the magistrate judges have direct experience with nearly all types of civil matters filed in our court.
Because our court is very busy, agreeing to proceed before a magistrate judge often means that the case will be resolved more quickly than if the case remained before a district judge.