Category Archives: basics

Negative Evidence: genealogy methodology and DNA

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.

Continue reading

Using shared cM counts to help find the common ancestor: part 1 of 3

Last month I suggested that soon I’d be sharing some results of a citizen science DNA project I’m working on. However, I realize now that the proposed blog draft is too long, with too many diversions to explain some basics that might help newer readers.

So I’m taking a step back and planning several short posts first. The theme is ‘Using shared cM counts to help find the common ancestor.’

Continue reading