During my fifteen-plus years of research, I have used a considerable number of family histories and compiled genealogies. There is one major lesson that I have learned - Watch out! Very few compilers have intentionally filled their books with misinformation or inaccurate lineages. Many of them, however, are loaded with errors.
Most of the genealogies that I have used deal with my New England ancestors. A few have mentioned those who originated in the Mid-Atlantic or Southern colonies. I tend to look for the most current (if you can call the 18th century current) of my ancestors and work back. That usually covers only three or four generations.
I have put together a few guidelines to consider when extracting information from these "labors of love" that the authors have created.
1. Check the date of publication. Those genealogies published during the late 1800s and early 1900s tend to rely more on family lore for the origins of the family. Undocumented stories of royalty, religious refugees, and glorious pasts tend to creep into the pages. Consider that the authors had fewer primary sources readily available and errors were more likely to occur. More recent and updated genealogies have the opportunity to contain newer and more reliable resources. (That doesn't necessarily mean that they will.)
2. Look at the sources cited. Many early works list the "begats" without telling the reader where the information came from. Was the source a family Bible, church records, Auntie's recollections, or simply not given? Some of the most reliable bits of information come from the deeds and probates cited in the books. Try to confirm the birth, death, and marriage dates with other sources. If you can, get copies of the deeds and probates and check them for more clues. You might be able to determine that a child was misplaced by the author by studying the wording of the deeds. Also check to see if the researcher relied on older compiled genealogies for information. There is no need to duplicate repeated erroneous material or to cite sources that have included previously cited works.
3. Realize the author's focus. Some genealogies focus on a single line of a family; others try to tackle a surname and include every line possible. If the focus is narrower, then the writer has less chance to include mistakes. He/she is likely to be more careful in dealing with three or four generations of a direct line. The more ambitious undertakings are more liable to suffer from misinterpretation of data or including previously published errors.
4. Read between the lines. If the author uses terms like "probably" or "believed to be" in a list of children or the spouse of a person, that means he/she was not sure that the child or spouse was correctly assigned to that individual. Investigate that question on your own. Checking the deeds and wills is a good start. I have seen authors misfire on a child when the clue was in a document included in the book.
5. Pay attention to places. Often the place of an event is inaccurate in terms of the historic timeframe. Check to make sure that the place given was indeed known by that name at the time of the event. A correct place name can be crucial in further research. For example, the birth place of one of my 4th great-grandfathers was taken from his Revolutionary War Pension file: Greenbriar Parish, Greenbriar County, Virginia. In 1751, when he was born, that region was still part of Augusta County, Virginia. For some reason he gave the place name as it was in 1832. His children were listed as born in Warren County, Ohio. The three eldest were born before Warren County was formed from Hamilton County. That meant early family records would be in Hamilton County files, not Warren. (The eldest was born on an Ohio River flatboat not in Hamilton County.) Check county and township formation dates, name changes for towns, and possible border changes for the states themselves.
6. Watch out for incorrectly identified progenitors. Every once in awhile you will come across a family history that contains real information, people, places, dates, and events, but are almost totally inaccurate. The reason? The author based his/her research on a bogus premise. A case in point, Descendants of Robert Lockwood by F.A. Holden and E.D. Lockwood (1889). The genealogy was based on the premise that Robert Lockwood was the progenitor of most of the New England Lockwood families. Unfortunately, they ignored Robert's brother Edmund entirely. Edmund came over with the Winthrop Fleet in 1630. His descendants were assigned to Robert. Needless to say, the book created a mess for Edmund's descendants. Donald Lines Jacobus dealt with the Lockwood Genealogy in a 1930 TAG article (Vol.31, p.222-228). Fortunately for Edmund's line, Harriet Woodbury Hodge published Some Descendants of Edmund Lockwood in 1978. Make sure the book you are using starts off correctly!
7. Make copies of the pertinent pages and refer back to them later. After you enter the material you extracted from the family history into your program and tuck it away in your files, don't forget about it. Pull the information out later and reevaluate it. A glaring error (born 1678, married 1690, for example) or an overlooked goody may jump out at you.
8. Check periodicals, mailing lists, family organizations, web pages and other sources for more current findings. Look for sources that might update those early family histories. Someone may have published an article about new findings on your family. A deed or Bible record of importance may have been located since the book's publication. Do a surname search on Google or Yahoo. Check PERSI for current or missed articles. Search Cyndi's List, US GenWeb, Familysearch.org or other internet sites. Visit a local library and browse the genealogy stacks. Chances are someone has published something new on that family that was not in the book.
There are probably a few other ideas that have momentarily escaped me. As I put together my research for publication, I try to make sure that everything fits and makes sense. I have tried to rely on data from compiled genealogies that are well documented within the work. Questionable information I have tried to cross-check or provide a disclaimer about its accuracy.
I have been amazed at details that I have missed on the initial viewing of the material. Something on a page copied in 1994 just does not ring true eleven years later. Those years of experience change perspective.
Compiled genealogies are a terrific resource. Like any other source, they have to be used with care. The battle cry for genealogists is "Cite Your Sources!" Make sure your source cited his/her sources.