Search billions of records on



Proper Use of Evidence and Source Citations

There is nothing more frustrating to a genealogist than locating details on an ancestor in a published book, Web page, or database, only to later find that the information is full of errors and inconsistencies. Grandparents are often linked as parents, women bear children at the tender age of 6, and often entire branches of a family tree are attached based on nothing more than a hunch or guess. Sometimes you may not even discover the problems until quite some time later, leading you to spin your wheels struggling to confirm inaccurate facts, or researching ancestors who aren't even yours.
What can we as genealogists do to a) be sure that our family histories are as well-researched and accurate as possible, and b) educate others so that all of these inaccurate family trees don't continue to procreate and multiply? How can we prove our family tree connections and encourage others to do the same? This is where the Genealogical Proof Standard established by the Board for Certification of Genealogists (BCG) comes in.

Genealogical Proof Standard

As outlined in "The BCG Genealogical Standards Manual", the Genealogical Proof Standard consists of five elements:

• A reasonably exhaustive search for all pertinent information
• A complete and accurate citation to the source of each item used
• Analysis of the collected information's quality as evidence
• Resolution of any conflicting or contradictory evidence
• Arrive at a soundly reasoned, coherently written conclusion

A genealogical conclusion that meets these standards can be considered proved. It may still not be 100% accurate, but it is as close to accurate as we can attain given the information and sources available to us.

Types of Genealogical Evidence

When collecting and analyzing the evidence to "prove" your case, it is important to first understand the different types of evidence:

• Direct vs. Indirect Evidence
Referring to the content of the record, direct evidence is information that points to a conclusion without a need for other evidence to explain or interpret it. Indirect evidence, on the other hand, is circumstantial information that requires additional evidence or thought to convert it into a reliable conclusion. Direct evidence usually carries more weight than indirect evidence.

• Primary vs. Secondary Evidence
Referring to the quality of the record, primary sources are records created at or near the time of an event by a person who had reasonably close knowledge of the event. Secondary sources, by contrast, are records created a significant amount of time after an event occurred or by a person who was not present at the event. Primary evidence usually carries more weight than secondary evidence.

• Original vs. Derivative Evidence
Referring to the provenance of the record, original sources are records that contribute written, oral, or visual information not derived – copied, abstracted, transcribed, or summarized – from another written or oral record. Derivative sources are, by their definition, records which have been derived – copied, abstracted, transcribed, or summarized – from previously existing sources. Original evidence usually carries more weight than derivative evidence.

These classes of evidence are rarely as clear-cut as they sound since a single source may actually be defined by more than one evidence class. For example, a death certificate is an original, primary source for the information directly relating to the death, but may also provide indirect evidence regarding items such as the deceased's date of birth, parent's names, and even children's names. The quality of the indirect evidence will have to be assessed based on who provided that information (if known), whether or not the informant was present at the events in question, and how closely that information correlates with other sources.

Evidence or Proof? How to Apply the Genealogical Proof Standard to Your Family Tree by Kimberly Powell,;

Cite Your Genealogy Sources: A Guide to Documenting Your Genealogy Research by Kimberly Powell,;


The BCG Genealogical Standards Manual by the Board for Certification of Genealogists
ISBN: 0916489922

Evidence! Citation & Analysis for the Family Historian by Elizabeth Shown Mills
ISBN: 0806315431


back to Tech Info page