[Editor's note: The following post from Jillaine Smith, one WikiTree's leading volunteer contributors, discusses the difference between original and derivative sources with a a special focus on the Puritan Great Migration.]
A major area of volunteer activity at WikiTree includes merging the many duplicate profile pages resulting from the early-stage uploading of GEDCOMs (before some very wise restrictions were put into place).
As we merge duplicate profiles and clean up the results, discrepancies in dates and relations are bound to arise, especially on profiles of people older than 200 years. This is due in large part because of the “diversity” of sources available. Profiles of early American colonists are particularly vulnerable to misinterpretation of these various sources.
And, as the field of genealogy/family history research has matured — especially in the last half of the 20th century — results of more recent and more thorough research have been published. Therefore, when looking at “evidence” for a particular piece of information such as a birth date, the maiden name of a wife, etc., it is crucial to understand the source of that information and learn how to judge its reliability.
Original vs. Derivative Sources
The first question I always ask is: Is this source ORIGINAL or DERIVATIVE?
An example of an original source is a 1650 church register, in which a pastor recorded the births, marriages and deaths of parishioners as they happened. A derivative is an extracted version of that, in which someone, at a (usually much) later date, transcribed the original, and perhaps re-ordered it by surname.
When transcriptions are made and edited, room for error increases. In New England, there are many such books upon which we rely that published vital records from colonial times through 1850. (And aren’t we also lucky that most of these have been digitized and made available online?!)
Derivative Sources to Watch Out For
Other derivative sources frequently used as evidence include:
- The IGI at www.familysearch.org. Quality varies; some records are extractions from original church records; others are entries without specific source information; great for clues.
- WorldConnect (at Rootsweb) / Ancestry.com Family Trees are user-contributed family trees of various quality. It appears that the bulk of these entries do not include any source information at all. I have heard more than a couple of people say: “But so many people claim she was born in Salem, so it must be true.” Ancestry.com, in particular, makes it very easy to download/copy an entire family tree. So in this case, quantity of a fact (nor that a tree is “published” online via a commercial entity) does not make it reliable in and of itself. Again, good for getting clues.
- The Millennium File. From the source information about this file: “The Millennium File is a database created by the Institute of Family Research to track the records of its clients and the results of its professional research… The Millennium File is a compiled source and is similar in form to other linked databases, such as Ancestry World Tree.” This translates to “very derivative” and, in fact, contains data several steps removed from the original. Such sources are great for clues for searching, but I would not trust anything without confirmation from at least one other (and closer-to-the-original) source.
While it might be obvious that an original source is more valuable than derivatives, they both have their value — we just need to review all the information we have in light of which type of source we used.
Another aspect to pay attention to is WHEN the source was created. Family genealogies published in the 1890s (as many genealogies were) typically do not include their own sources, so it can be difficult to judge how their reliability. Family genealogies published after, say, 1930, tend to follow better documentation processes.
Further Reading on Sources and Genealogy
THE definitive work concerning the use of sources is Elizabeth Shown Mills’ Evidence Explained. The author also maintains an active Facebook page where she posts daily tips on sources and their usage.
In addition, noted genealogist Thomas W. Jones has published Mastering Genealogical Proof which is available in late May 2013. Throughout the book, Jones not only emphasizes the important of scrutinizing sources, but also how to properly cite those sources.