[update: 9 Feb 2012. Ancestry.com tells me they are revising the glossary and the old pages should be gone within the month. Thanks!]
This screen shot is from Ancestry.com's learning center. This is their glossary definition for "secondary evidence" and "secondary source."
Apparently they've not been reading Evidence Explained, by Elizabeth Shown Mills. She (as well as others in the field, including yours truly) classifies information as:
- primary--firsthand
- secondary-secondhand
Sources are:
- original or
- derivative
Evidence is:
- direct or
- indirect
I won't blather on about the definitions here or how to use them in actual research. Mills' book explains them in some detail and we use them "in the field" in Casefile Clues all the time. We even look at some voters' registrations from the 1890s in the next issue and discuss the information as being primary or secondary in nature.
Too bad Ancestry.com's not on top of things. The first edition of Mills' book came out in 2007!