Both professional genealogists and casual family researchers need genealogy standards in order to get their genealogy right. Without standards, inaccuracies and myths can be created and perpetuated. Many of these errors can be avoided by working to genealogy standards.

Genealogy standards have evolved over many years. Family historians originally tapped into the legal field and applied its preponderance of evidence principle to their work. Subsequently, genealogists recognized this approach was not the best fit for family history as an accumulation of evidence is not always sufficient for proof. From 1997 to 2000, BCG analyzed, defined, and combined the best genealogy practices and created the Genealogical Proof Standard. In 2000, BCG published The BCG Genealogical Standards Manual.[1] After further refinement, BCG published Genealogy Standards in 2014.[2]

For a deeper understanding of the refinements from 2000 to 2014, see Genealogy Standards Comparison Chart: New versus Old Standards and Genealogy Standards Comparison Chart: Old versus New Standards. 

The 2021 second edition revised reflects the fact that the practice of genealogy is not static, but evolves as new developments and technologies emerge. Genealogy’s standards must keep pace also. Responding to this decade’s spate of advancements in the practice of genetic genealogy, BCG has modified four existing standards and added seven new standards to guide the use of DNA evidence in genealogical analysis. BCG also has updated the Genealogist’s Code to address the protection of individuals who provide DNA samples. New terms added to the glossary reflect the specialized language associated with DNA evidence. For a comparison the 2014 and 2021 standards click here.

Following these standards helps family historians research thoroughly, document properly, analyze, and correlate evidence, resolve conflicts, and write clear and convincing genealogical works.

Read more about the > Genealogist’s Code of Ethics

What Are Standards?

Standards are the best practices for genealogy. They enable all genealogists—not just BCG associates—to come as close as possible to what actually happened in history.


Genealogical Proof Standard (GPS)

To reach a sound conclusion, we need to meet all five components of the GPS.

1. Reasonably exhaustive research.
2. Complete and accurate source citations.
3. Thorough analysis and correlation.
4. Resolution of conflicting evidence.
5. Soundly written conclusion based on the strongest evidence.[3]

The GPS overarches all of the documentation, research, and writing standards described in Genealogy Standards, and is applied across the board in all genealogical research to measure the credibility of conclusions about ancestral identities, relationships, and life events.[4]


Fox, Judy Kellar. “Ten-Minute Methodology: Are You Searching or Researching?” BCG SpringBoard blog. 8 July 2015.

Fox, Judy Kellar. “‘Reasonably Exhaustive’—How Do We Know We’re There?” BCG SpringBoard blog. 17 September 2015.

Fox, Judy Kellar. “Ten-Minute Methodology: What is ‘Reasonably Exhaustive’ Research?” BCG SpringBoard blog. 3 September 2015.

Jones, Thomas W. “The Genealogical Proof Standard: How Simple Can It Be?” OnBoard 16 (September 2010): 17–18, 20.

Jones, Thomas W. Mastering Genealogical Proof. Arlington, Virginia: National Genealogical Society, 2013.

Leary, Helen F. M. “Evidence Revisited—DNA, POE and GPS.” OnBoard 4 (January 1998): 1–2, 5.
Note: some dated terminology, but an important explanation why genealogists no longer use a “preponderance of the evidence” standard.

Jones, Thomas W. “New Standards or Old? Guidelines for Effective Research and Family Histories.” Board for Certification of Genealogists, sponsor. Legacy Family Tree Webinars.

Sayre, Pamela Boyer. “Enough is Enough, Or Is It?” Board for Certification of Genealogists, sponsor. Legacy Family Tree Webinars.

The GPS is illustrated in many articles published in the scholarly journals such as the:
– National Genealogical Society Quarterly (NGSQ),
– New York Genealogical & Biographical Record,
– New England Historical and Genealogical Register,
The American Genealogist, and
The Genealogist.


> Read more about Standards for Documenting

> Read more about Standards for Researching

> Read more about Standards for Writing

> Read more about Standards for Educators


Links to Related Genealogical Organizations: Ethics and Standards

BCG does not endorse the code of ethics or the standards of the following related genealogical organizations. The links to the codes and standards of these organizations are provided as a courtesy.

> Association of Professional Genealogists (APG), “Code of Ethics and Professional Practices”

> Genetic Genealogy Standards

> National Genealogical Society (NGS)

> International Commission for the Accreditation of Genealogists (ICAPGen)

> International Association of Jewish Genealogical Societies (IAJGS)

> The Australasian Federation of Family History Organisations, Inc. (AFFO) Code of Ethics

> Society of Genealogists (UK) “Standards and Good Practice in Genealogy”


BCG Webinars on Legacy Family Tree

BCG partners with Legacy Family Tree to produce instructional hour-long webinars by BCG associates. The webinars are free when first presented each month and for a limited time afterwards. Access the BCG Webinar Library at Note: BCG receives a commission if a person registers for or buys a webinar using the affiliate link.


[1] Board for Certification of Genealogists, The BCG Genealogical Standards Manual (Orem, UT: Ancestry, 2000).
[2] Board for Certification of Genealogists, Genealogy Standards, fiftieth-anniversary edition (Nashville, TN: Ancestry, 2014).
[3] Board for Certification of Genealogists, Genealogy Standards, second edition, revised (Nashville, TN: Ancestry, 2021), 1–3.
[4] Board for Certification of Genealogists, Genealogy Standards, second edition, revised (Nashville, TN: Ancestry, 2021), 1.