A sedimentation rate is performed by measuring the rate at which red blood cells (RBCs) settle in a test tube. The RBCs become sediment in the bottom of the test tube over time, leaving the blood serum visible above. The classic sedimentation rate is simply how far the top of the RBC layer has fallen (in millimeters) in one hour.
The scope of genealogy, however, goes well beyond family trees; extending into areas of law, technology, event planning and medicine. Hiring a genealogist can be costly, so you must conduct your own research before hiring someone to do research on your behalf.
So, should you hire a private investigator in your case? That all depends, and it depends on a lot of things. Really, before you even consider hiring an attorney, you should talk to an attorney, one-on-one, to make a decision about what is right for you in your unique circumstances. What are your goals in your divorce?