Thursday, 15 October 2015

Communicating Uncertainty in Genealogy

In genealogy when, despite best efforts toward a reasonably exhaustive search, you're still faced with conflicting evidence the genealogical proof standard leaves you stranded. If pressed a professional genealogist will often give her opinion using descriptive terms regarding degree of uncertainty. However, there is no professional standard or even terminology. That means when one professional says she is confident another may express it as likely. Do these mean the same thing or is one more probable than another?

Dr. Susan Jocelyn, a cognitive psychologist from the Decision Making with Uncertainty Lab at the University of Washington, has spent many years studying how people make decisions based on uncertainty. She has dispelled many misunderstandings about the public's perception of uncertainty.

According to her research uncertainty estimates give people a better idea of what to expect both in terms of the range of possible outcomes as well as the amount of uncertainty in the particular situation. She answers YES to each of the following questions.

1. Can people understand expressions of uncertainty?
2. Do people make good decisions with uncertainty information?
3. Does uncertainty information increase trust?

Dr. Joslyn's work has been done mostly in the context of understanding probabilistic weather forecasts which long ago adopted probability of precipitation in public weather forecasts.

Further objections to the use of quantification of uncertainty, or probability, in genealogy have been addressed by Paul Jones as I reported on the blog in May last year.

Snyder, B, Schneider, S, 2015: Communicating Uncertainty to Users of Weather Forecasts, CMOS Bulletin SCMO, Vol. 43, No. 5.

1 comment:

Debbie Kennett said...

I think you make some very valid points here. There ought to be some way of quantifying the level of confidence we have in our genealogical assumptions, though I'm not sure of the best way of doing this. In case it's of interest to your readers Sense About Science have published a very useful leaflet on "Making Sense of Uncertainty":