Evaluating the Evidence for Genealogy Research | Mishawaka-Penn-Harris Public Library 

Evaluating the Evidence for Genealogy Research

Evidence analysis starts with a three step classification:

  1. The type of information
  2. The type of evidence
  3. The type of source

How much merit is assigned to each piece of evidence will be dependent on the reliability of the sources, the origins of their information, and how it correlates with other sources. When assigning weight to evidence it is important to consider WHO gave that information. A mother reporting a death of her child would be more accurate than that of a neighbor. You should also consider WHY the record was created. An age in a census may be more accurate than an age on a military record because the individual may have lied about his age so he would be accepted by the military.

View a printable PDF version of this guide.

Types of Information:

  1. Primary Sources: Statements made by individuals who were a knowledgeable participant in an event or an eye witness to it. It was made at or close to the time of the event. Examples: Birth certificate, deeds, wills, military records, passenger lists.
  2. Secondary Sources: Statements made by individuals who were not actual participants in an event or did not actually witness an occurrence. This includes family oral traditions, abstracts, and transcripts of records and online genealogical databases.

    Examples: A death certificate contains both primary and secondary sources. The information about the death is primary but the information about the deceased's parents and birth is secondary because the informant may not have known the parents or been a witness to the deceased's birth.

Types of Evidence:

  1. Direct Evidence: This refers to where the information came from. If the birth information came from the birth certificate then it is direct evidence.
  2. Indirect Evidence: This is information that requires corroboration. It provides enough information to allow you to form a hypothesis and, when combined with other evidence, reach a reliable conclusion.

    Example: You can't find a birth certificate of your grandfather but you can determine an age using a census and a birth announcement. The census doesn't give his exact date of birth and the birth announcement gives a birth date and his parents' names but does not list his name. By using both indirect records, you can reach a reasonable conclusion as to his probable date of birth.

Types of Sources:

  1. Original: Original records were created to record a specific event. They were made at or near the time of the event and their informants were present at the event. Anything that is an accurate and exact image of the original document can be considered an original record, such as scanned images.
  2. Derivative: Derivative records contain information whose informant was not present at the event. This includes copied, abstracted, transcribed, and compiled information. In general, the further removed the copies are from the original document, the more likely errors have been introduced.

    Examples: Online transcripts of the census and indexes of those transcripts.

Evaluating evidence is not as straightforward as all original records outweigh derivatives. In fact, original records are not inherently more accurate than derivatives. Nor is primary information more correct than secondary information. Thus, it's important to remember that each record does not stand alone. Every effort should be made to find additional resources to corroborate the information.

In an effort to gain a greater understanding of the process in analyzing evidence, try looking at the guidelines created by Elizabeth Shown Mills from her book Evidence Explained: Citing History Sources from Artifacts to Cyberspace. These guidelines will show that we must consider WHO were the informants that supplied the information, what circumstances surrounded WHY the record was created, and the reliability in the creation of the document.

Guidelines for Analyzing Evidence:

  1. Direct evidence is easier to understand, but indirect evidence can carry equal weight.
  2. Reliable genealogical conclusions are based on the weigh-not quantity-of the evidence found.
  3. Evidence should be drawn from a variety of independently created sources.
  4. Original source material generally is more reliable than derivative material.
  5. The reliability of derivative work is influenced by the degree of processing it has undergone.
  6. The purpose of a record and the motivation of its creators frequently affect its truthfulness.
  7. The most reliable informants have firsthand knowledge of the events to which they testify.
  8. The veracity and skill of a records creator will have shaped its contents.
  9. Timeliness generally adds to the document's credibility.
  10. Penmanship can establish identity, date, and authenticity.
  11. A record's custodial history affects its trustworthiness.
  12. All known records should be used and a thorough effort made to identify unknown materials.
  13. The case is never closed on a genealogical conclusion.

A Few Generalizations When Comparing Different Records:

  1. Normally microfilm, scans, and photocopies have more weight than handwritten or typed transcriptions and abstracts.
  2. Normally a readable photograph of a tombstone inscription has more weight than handwritten notes made from tombstone inscriptions.
  3. Normally transcriptions made closer to the time of the event have more weight than transcriptions made further away in time from the event.


Mills, E.S. (2009). Evidence Explained: Citing History Sources from Artifacts to Cyberspace. Baltimore: Genealogical Publishing Company.

Powell, Kimberly. (2006). The Everything Family Tree Book: Research and Preserve Your Family History. Avon: Adams Media.

Rose, C. (2009). Genealogy Proof Standard: Building a Solid Case. San Jose: CR Publications.

Join us on Facebook Join us on Instagram Join us on Youtube