Last time I posted about negative findings and negative evidence, in traditional document-based genealogy and in genetic genealogy. Link here.
Now for the fun stuff – a cool use of negative evidence in *autosomal* DNA. For this exercise, the research question is: from which grandparent did the DNA segment in question originate?
Genetic genealogy, like documentary genealogy, can result in negative findings and negative evidence. What’s the difference? (It wasn’t that long ago that I was confused about that too!)
You start with a research question and a source. ‘Negative’ means the information you’re looking for in the source isn’t found. A negative finding doesn’t help you answer your research question. Negative evidence does. You may have to understand the context to know which one you have. Some examples, with document-source genealogy and DNA-source genealogy, may help.
“The best laid schemes o’ mice an’ men / Gang aft agley”, as the poet [Robert Burns] says.
In other words, herein lies what worked in my project to identify a good cM threshold for “false positives”… and what didn’t.