Sunday, 14 October 2012

How many errors in your genealogy?

If you think your carefully-researched genealogy is error free -- that's a delusion! It's not a question of whether there are errors but how many.

If there are 1000 people in your family tree, each with say ten facts: first name, last name, father's name, mother's name, birth date, birth place, marriage date, marriage place, spouse name, death date, death place, that's already more than ten and you could add many more. With 10,000 facts if you have 99.9% confidence each fact is correct then 10 will likely be erroneous.

The error rate will escalate massively if you made an error in identifying the parent - such as hiding an illegitimate birth by claiming a young woman's child was her mother's - which makes all upstream facts incorrect.

Even DNA evidence has problems, as explained in an article 'DNA evidence, far from an open and shut case' in the UK Guardian newspaper.

The influence of these biases is likely to have a much wider effect than just on fingerprint analysis. Dror notes that they could affect any area where "the human examiner is the main instrument of analysis", including fingerprinting, DNA, CCTV images, firearms and document examination. "The contextual influences are many and they come in many forms," says Dror. "Many… [if not] most of the forensic areas are vulnerable." These warnings have met with a frosty welcome from many forensic scientists who, despite the evidence, have balked at the suggestion that they could be anything less than objective.
 Would the welcome from professional genealogists assiduously following the genealogical proof standard be any less frosty?

1 comment:

Persephone said...

I've always thought the Genealogical Proof Standard should be called the Genealogical Evidence Standard. Is there really such a thing as "proof" in family history?

I do review my research -- particularly the direct line because if that's wrong, everything is wrong. I find mistakes every damned time.

I think this fits in with your discussion of exclusive online research vs time spent in library, archives, and family history society activities. What I'm seeing increasingly (especially over the past three years or so) are online family trees with fatal errors, that is, a major mistake in the direct line which means, of course, a tree full of someone else's relatives. People seem to copy other people's research without checking sources for themselves, asking questions, or even making contact with tree-owners. Being online seems to dampen courtesy and caution.

One of the chief benefits of regular "face-time" in BIFHSGO meetings for me is that afterwards I go back and re-check my data, using the new web site, technique, or information I've acquired during a talk or discussion. Promptly uncovering new errors, of course...