Why Online Family Trees Can Be Wrong

Online family trees can feel like a gift. With a few clicks, entire generations appear—names, dates, places, even stories—already assembled by someone else. It’s tempting to assume that if a tree exists on a major genealogy website, it must be accurate.

But in reality, online family trees are starting points—not proof. If I could emphasize anything to new family historians, it would be that.

Platforms like Ancestry and FamilySearch allow users to share and copy trees freely. While that collaboration can be incredibly helpful, it also means that errors spread quickly, often without anyone realizing it.

The Biggest Pitfall: Copying Without Verifying

One of the most common mistakes in genealogy is copying information from another person’s tree without checking the records behind it.

Here’s how it usually happens:

• One person guesses at a parent or spouse

• That guess is added to a public tree

• Others copy it into their own trees

• The same incorrect information appears again and again

Before long, the error looks “confirmed” simply because it’s everywhere.

But repetition does not equal accuracy.

As an example of how this can take on a life of its own, in National Genealogical Society Quarterly Volume 113, No. 2 from June 2025, an article by Thomas W. Jones, PhD, CG, CGG, FASG titled “History of a Genealogical Error: The Misattributed Parentage of Atlanta Pioneers, Meredith and Merrell Collier,” describes an error that began in a book in 1887 with a speculative statement and has since extended into over a thousand online trees and applications for lineage societies like the Daughters of the American Revolution. Jones breaks down what the actual records say and how this error was perpetuated over nearly 150 years.

Trees Aren’t Sources — Records Are

A family tree is a conclusion. Good genealogy requires understanding how that conclusion was reached.

Reliable research is built on original or derivative records such as:

• Census records

• Birth, marriage, and death certificates

• Church registers

• Probate files and wills

• Land deeds

• Newspapers

• Military records

These documents place real people in real places at specific points in time. Without them, a tree is simply an untested hypothesis.

If a tree doesn’t clearly connect individuals using records, it should be treated cautiously—no matter how polished or detailed it appears. This is exactly the issue with the case Jones described in the article I mentioned above. Two publications referenced a conclusion with no supporting evidence between 1887 and 1911, and now all of these online trees repeat the error because the folks creating them aren’t confirming what the original, contemporary documentation of their ancestors says.

Why Even Well-Meaning Trees Can Be Wrong

Most incorrect trees aren’t created out of carelessness. They’re created because genealogy is genuinely hard. This is especially true the further back in history you go, or if your research subject is in a community that has historically not been documented comprehensively, such as enslaved Black people, Native Americans, or women.

Common challenges include:

• Multiple people with the same name in the same place

• Ages and birthplaces changing from record to record

• Missing census entries

• Families moving frequently

• Cultural naming traditions that repeat names across generations

Without careful analysis, it’s easy to attach the wrong record—or the wrong parents—to the right person. Don’t get me started on how many Michael and John Rourkes there are in my family tree, not to mention out in the world.

Hints and Algorithms Aren’t Proof

Automated hints on genealogy websites can be useful, but they are not evidence. Algorithms suggest connections based on patterns—not historical context.

A hint should always prompt a question:

Does this record actually belong to my person?

Before accepting a hint, it’s important to compare:

• Dates and locations

• Family members listed

• Occupations

• Migration patterns

If the details don’t align, the record may belong to someone else entirely. You can always save a link in a running note or spreadsheet to look at later after additional research. Some genealogy sites even have a place to save miscellaneous records, like FamilySearch’s Source Box.

How to Use Online Trees Wisely

Online trees can be valuable when used carefully. Think of them as research leads rather than answers.

A good approach is to:

• Use trees to identify possible records

• Look for attached sources (and evaluate them yourself)

• Verify every fact with documentation

• Keep notes about what is proven vs. unproven

This method keeps your research grounded while still benefiting from shared knowledge.

Building a Tree You Can Trust

Strong genealogy is slow, thoughtful, and evidence-based. It values accuracy over speed and understanding over convenience.

When your research is supported by records, you’re not just collecting names—you’re preserving a family’s true story.

Not sure whether the information in your family tree is accurate? Starting with records—not assumptions—can help clarify what’s proven and what still needs research. And if you want help, I’m here.