Evidence Analysis Explained: Digging Into Genealogical Sources

This article is the first in a three-part series that explores evidence analysis concepts through easy-to-understand definitions, probing questions to be utilized while researching, and real-world examples to illustrate the concepts that will help you analyze genealogical evidence like a pro! 

What does a genealogist do, anyways?

When I talk with those unfamiliar with genealogical research, they are often surprised by all that goes into what we do as professional genealogists. Rather than simply “looking up” family trees online, our work is characterized by the thorough, detailed, and careful examination of historical documents in relation to a specific research problem. These documents are located through databases, research libraries, and archival facilities (in all shapes and forms) from across the world.

As professional genealogists, we understand that thorough genealogical research includes properly analyzing the evidence to draw research conclusions. When evidence analysis is utilized, it facilitates sound conclusions concerning the research problem. Author and fellow genealogist Elizabeth Shown Mills is well known for distilling the concepts of evidence into distinct categories which ensure thorough, careful, and accurate interpretations of evidence are applied to our research. Her work on the subject can be read in “QuickLesson 17: The Evidence Analysis Process Model” and in her book Evidence Explained: Citing History Sources from Artifacts to Cyberspace[1]

The first article in this three-part series will provide an overview of the evidence analysis process and discuss the concept of “Sources” in genealogy. The second article will investigate the concept of “Information” and the third will discuss “Evidence” as well as “Defensible Conclusions.”

What is Evidence Analysis?

Evidence analysis is the mechanism—comprised of critically evaluating sources, information, and the nature of the evidence—that leads a researcher to a defensible conclusion. Because the most basic purpose of genealogy is reaching defensible conclusions about our ancestors that means evidence analysis is pretty important. Each of those categories—sources, information, and evidence—have three subcategories. How these categories work together to reach defensible conclusions is illustrated by the following chart:

After we have thoroughly examined the sources, information, and evidence we can arrive at a defensible conclusion concerning the proposed answer to the research question. Note that a defensible conclusion is only reached if the Genealogical Proof Standard (GPS) has been applied to the research. The GPS will be discussed in our third post in this series. It is worth mentioning now, however, that the first component of the GPS is “reasonably exhaustive research” which means that frequently a research problem will be examined over the course of several research sessions before a defensible conclusion can be reached.

Evaluating Genealogical Sources

This first category in the evidence analysis process deals with the document itself, not the data the document transmits. Examining the document is necessary because doing so will assist in determining the credibility of the information the document preserves. There are three categories of sources: 1) Original, 2) Derivative, and 3) Narrative. Definitions for these categories are given in the chart below:

The following questions are of assistance when evaluating sources:

What is the format of the source?

Knowing whether the source is the original sexton’s record book, or a later transcription derived from the original can be of immense value. An original source, by its very nature, is more reliable than a derivative because the original was the first instance of a document about an event while a derivative was created from the original (or from another derivative). That extra step (or steps) in the creation process between an original and derivative source allows for human error. Derivative sources may come in several different formats, including transcriptions, extracts, abstracts, indexes, or databases.

Narrative sources are items such as a history book or a written family history (or reports like those created by Legacy Tree Genealogists). Narrative sources rely on research done in any or all of the source types.

Does the format impact the legibility of the source?

While original sources should always be sought out, sometimes they have deteriorated so much that they are no longer legible. In these instances, it may be necessary to rely on a derivate source that was created when the original was still legible. A prime example would be a grave marker that is currently illegible, but a cemetery transcription done previously may have preserved the information.

Does the derivative source appear reliable?

Sometimes an original source is not available for consultation and a derivative must be used. In such cases, the reliability of the derivative should be considered. Some derivative sources were created with great care and attention to detail others were done hastily which allows for more errors.  Do different sources list conflicting information? Check out our article on how to resolve conflicting information in sources. Note also that although the derivative may be reliable, the original source frequently reports more information.

Does the narrative’s author provide references?

When evaluating a narrative source, the researcher should determine whether the author provided citations to support his or her claims. The citations convey the reliability of the author’s conclusions. If the conclusions appear sound and the citations reveal that appropriate sources were consulted, then the researcher may be comfortable citing the narrative author. If no citations were provided or if the citations were inadequate, then the researcher will likely choose to rely on other sources.

What was the narrative author’s scope?

If consulting a narrative source—a published family history, a history book, a research report, etc.—it is necessary to consider whether the author’s scope was appropriate for the research question. This can be done by considering the format of the narrative; are there items such as in-text citations, footnotes, endnotes, or a bibliography? If the author did not consult the best record types for a research problem, missed important collections, or did not utilize enough sources then the researcher will likely choose to supplement the author’s work with additional research.

Examples of Types of Genealogical Sources

Original Source

This birth certificate is a high-quality digital reproduction of the original certificate kept by the county recorder and is, therefore, considered an original source.[2]

Derivative Source

This clipping from an online grave memorial is a derivative source because it is not the original sexton’s record book nor does the memorial have a high-quality reproduction of the grave marker.[3]

Narrative Source

This excerpt from a genealogical research report demonstrates a narrative source because the author presents new conclusions based on his research. The citations placed in footnotes allow the reader to easily evaluate the author’s work.

If genealogists, whether hobbyist or professional, do not apply rigorous standards to our research then our genealogy turns into (at best) fun stories, regardless of whether they are true. Because we at Legacy Tree Genealogists are committed to providing clients accurate family histories, our researchers employ industry standards and practices to their work. Any genealogist can, and should, apply the same standards to his or her research.

We have carefully selected the members of our team at Legacy Tree Genealogists to make sure they are experts at analyzing evidence to draw accurate research conclusions. We’d love to help you with your family history, whether we’re breaking down brick wall mysteries, finding your biological parents, or just starting from scratch finding the stories about your ancestors. Contact us today for a free quote.

[1] Elizabeth Shown Mills, “QuickLesson 17: The Evidence Analysis Process Model,” Evidence Explained: Historical Analysis, Citation & Source Usage (https://www.evidenceexplained.com/content/quicklesson-17-evidence-analy… :  11 January 2019); and

Elizabeth Shown Mills, Evidence Explained: Citing History Sources from Artifacts to Cyberspace (Baltimore, Maryland: Genealogical Publishing Company, 2017).

[2] Delaware State Birth Records, 1861-1922 (image and transcription), birth certificate for Margaret Jane Smith, 28 September 1862, New Castle County, Delaware, http://www.familysearch.org, accessed June 2019.

[3] Find A Grave (images and transcription), Rose Hill Cemetery, Fort Gaines, Clay, Georgia, headstone and memorial for Ann Jones, 1875-?, memorial no. 82234588, http://findagrave.com, accessed June 2019.

[4] Robert M. Call, “Report on Research Concerning Four Generations of the Call Family,” typescript, 2015, original in author’s possession.