How many sources do you need to make a good genealogical conclusion?

Geoff Rasmussen

12 Sep 2007

Sometimes we are happy to find just one source that provides information about a genealogical fact. Other times we might be delighted to learn that all ten sources you reviewed stated the same information. Which is better – quantity or quality of sources?

In researching Joshua Marsden Thompson’s family, I found a reference to a William Marsden Thompson in a compilation that had been published online. Knowing that Marsden is not that common of a name, I investigated further. I found numerous compilations online – published genealogies, message boards and mailing lists – all providing the identical given name.

Because all of these sources gave the same information does not provide the evidence to make a sound conclusion. In fact, Elizabeth Shown Mills, in her new book Evidence Explained, teaches:

We cannot base conclusions on the number of times a source or fact is cited; a dubious factoid repeated over and again cannot outweigh a reality correctly reported by a single, impeccable source….Multiple sources for a particular statement confirm each other only when each is a reliable source of independent origin offering firsthand knowledge.

Applying these concepts, I located the researcher who originally published information about William. I politely requested that they share with me where they found information about William’s name. They said they found his name on the headstone where he was buried. My interest naturally led me to asking if they would send me a photo of the headstone. When the photo arrived, they apologized because the name was not actually William, it was Joshua. They stated that somewhere along the way, they mixed up the names in their data entry.

A headstone is still probably not the best source to offer firsthand knowledge of a name, but had I relied on information that came from this publication, even though it was confirmed by many other sources, I would have propagated the same incorrect information.

Comments (10)

I have only been compiling my family tree for about 2 years. Like Laminda I have done the same as many did when they started, much of my info has come from trees & websites compiled by a whole assortment of people. I have recorded very little documentation. Where I have found my own evidence I haven’t recorded the source so I hope my memory doesn’t fail me. Thanks for all the advice listed here. Looks like I’ve got a lot of ‘Documentation’ work ahead of me.

Dear Laminda,
I was in your situtation about 5 years ago. I had spend 10 years gathering information but I didn’t understand the importance of documenting my sources until after I took several courses through Brigham Young’s continuing ed program. I had to go back and pretty much re-research everything.
Start with your direct line and look at every fact you have recorded and backtrack. Find the supporting evidence. If you can’t, don’t wipe out the info (yet). Just make a notation that the information is UNVERIFIED! Obviously you got the info somewhere but it might take you a while to figure it out 🙂 🙂 🙂 Concentrate on your direct line and after you have that fixed then you can branch out to the other folks in your tree.
Michele Lewis

I whole heartedly agree with all the comments. I try to put sources to all the information I collect. also when I publish it on my website I make sure I also include all the source information so people can check it out themselves. This is very useful because I have had a number of corrections made by people contacting me through the website who have provided additional information.

I have a rather large genealogical database with very little documentation. What is the best way to go about cleaning this up? I think I have to create a new database and copy data over as I have it documented. The other option is to update the current database with sources as I find them. What would y’all recommend?

I understand what you all are talking about. I am very new to this stuff. I did not realize that i needed to verify everything and not trust that someone else did. I have deleted so much, and added to, and had to delete that, that I rather print out what I find on the internet. Then I go through sourcing it, and verfiying it myself. Things I know for a fact like my father and father – in – law passing I put me as the source. what i get from other people I verify before adding. I spent alot time redoing my tree from miss given info. like some one gave me a date that had to be wrong because he died and married before he was born, or he was born and married before he died.
I also feel closer to the people I add, because like one said they become more than a name. I feel proud of my roots and my hertiage. I do not want to rush something, I want my information to be accurate. I even verify what i had gotten from my Dad, some of his dates do not add up. So i verify, source it then add. At the top of my tree i put, please do not take my word please verify all info…

I couldn’t agree more. When I began my search over 30 years ago now, I started with family recollections (as most of us did) and took the information as “gospel”. Not knowing the value of documentation, I didn’t take the time to verify what I already had received from family and begun my search from there. Boy have I marched down many a wrong road! Even today I am finding the “correct” information about my grandfather that was given me in error by my mother . . .information that was “verified” by numerous family members, but proven wrong by the documents. Family legends generally have a point of truth somewhere, but without the documentation you can never be sure if your “story” is fact or fiction.

I learnt this the hard way when I first started tracing my family history and it’s amazing how many people out there have done the same. But now any new facts I get from other researchers I verify by viewing the original sources before they make it into my tree. Mind you I’m still reviewing facts from when I first started…
…I might get them all verified one day!

I totally agree, in connecting lines in from other family trees, I have parents married to grandparents or dates that at the same going on and on that are incorrect. Each time I upload a name into my tree, I go out and try to verify all information. This alone could take years to correct information.

I learned the hard way not to trust without proof. I had a very niece person contact me about my great great great grandmother and realtives. I was farely new to genealogy and checked out there website and just added their information to mine. Then I started my documentation trail on my great great great grandmother (just for proof sake) and what you know according to her death certificate the information this person shared was way off the mark. I went to the archives and dug up her baptismal record yep her parents were the same people listed on her death certificate and are buried two rows and four plots away from her parents. I had to delete hours of work that ended up to be a waste of time when I could have taken the same amount of time to discover the facts. Now I believe nothing without a primary source or two secandary sources.
My feelings reflect Cynthia’s, it is easier to add this web found information to my tree, but I want the information I add to be my family and I want it sourced. Yes, it takes longer, but at least I know that when I share my information is valid. And I agree again with Cynthia the longer you take with each person you research they become more than just name they are family.

How true! There are so many people out there who want to make a tree anyway they can, just to complete the project. Those are the people who will send out undocumented data, because they found a surname that was the same or similar to the one they were searching. Any time I receive new information, I start looking for something to document the name, dates and locations. It would be very easy to just add this new information to my tree, but I don’t and won’t do that. It takes longer to build your tree, but when it’s done this way, you are certain it is your family. I also feel that I get to know this long ago person just a bit better. They become more then a name in my tree.

TM
Tony McGurk

17 years ago

I have only been compiling my family tree for about 2 years. Like Laminda I have done the same as many did when they started, much of my info has come from trees & websites compiled by a whole assortment of people. I have recorded very little documentation. Where I have found my own evidence I haven’t recorded the source so I hope my memory doesn’t fail me. Thanks for all the advice listed here. Looks like I’ve got a lot of ‘Documentation’ work ahead of me.
ML
Michele Lewis

17 years ago

Dear Laminda,
I was in your situtation about 5 years ago. I had spend 10 years gathering information but I didn’t understand the importance of documenting my sources until after I took several courses through Brigham Young’s continuing ed program. I had to go back and pretty much re-research everything.
Start with your direct line and look at every fact you have recorded and backtrack. Find the supporting evidence. If you can’t, don’t wipe out the info (yet). Just make a notation that the information is UNVERIFIED! Obviously you got the info somewhere but it might take you a while to figure it out 🙂 🙂 🙂 Concentrate on your direct line and after you have that fixed then you can branch out to the other folks in your tree.
Michele Lewis
J
Jude

17 years ago

I whole heartedly agree with all the comments. I try to put sources to all the information I collect. also when I publish it on my website I make sure I also include all the source information so people can check it out themselves. This is very useful because I have had a number of corrections made by people contacting me through the website who have provided additional information.
T
Tobin

17 years ago

I have a rather large genealogical database with very little documentation. What is the best way to go about cleaning this up? I think I have to create a new database and copy data over as I have it documented. The other option is to update the current database with sources as I find them. What would y’all recommend?
LR
Laminda Roberts

17 years ago

I understand what you all are talking about. I am very new to this stuff. I did not realize that i needed to verify everything and not trust that someone else did. I have deleted so much, and added to, and had to delete that, that I rather print out what I find on the internet. Then I go through sourcing it, and verfiying it myself. Things I know for a fact like my father and father – in – law passing I put me as the source. what i get from other people I verify before adding. I spent alot time redoing my tree from miss given info. like some one gave me a date that had to be wrong because he died and married before he was born, or he was born and married before he died.
I also feel closer to the people I add, because like one said they become more than a name. I feel proud of my roots and my hertiage. I do not want to rush something, I want my information to be accurate. I even verify what i had gotten from my Dad, some of his dates do not add up. So i verify, source it then add. At the top of my tree i put, please do not take my word please verify all info…
PL
Penni Luntsford

17 years ago

I couldn’t agree more. When I began my search over 30 years ago now, I started with family recollections (as most of us did) and took the information as “gospel”. Not knowing the value of documentation, I didn’t take the time to verify what I already had received from family and begun my search from there. Boy have I marched down many a wrong road! Even today I am finding the “correct” information about my grandfather that was given me in error by my mother . . .information that was “verified” by numerous family members, but proven wrong by the documents. Family legends generally have a point of truth somewhere, but without the documentation you can never be sure if your “story” is fact or fiction.
DH
Dave Hunt

17 years ago

I learnt this the hard way when I first started tracing my family history and it’s amazing how many people out there have done the same. But now any new facts I get from other researchers I verify by viewing the original sources before they make it into my tree. Mind you I’m still reviewing facts from when I first started…
…I might get them all verified one day!
DC
Deborah Criddle

17 years ago

I totally agree, in connecting lines in from other family trees, I have parents married to grandparents or dates that at the same going on and on that are incorrect. Each time I upload a name into my tree, I go out and try to verify all information. This alone could take years to correct information.
KT
Katie Tennstedt

17 years ago

I learned the hard way not to trust without proof. I had a very niece person contact me about my great great great grandmother and realtives. I was farely new to genealogy and checked out there website and just added their information to mine. Then I started my documentation trail on my great great great grandmother (just for proof sake) and what you know according to her death certificate the information this person shared was way off the mark. I went to the archives and dug up her baptismal record yep her parents were the same people listed on her death certificate and are buried two rows and four plots away from her parents. I had to delete hours of work that ended up to be a waste of time when I could have taken the same amount of time to discover the facts. Now I believe nothing without a primary source or two secandary sources.
My feelings reflect Cynthia’s, it is easier to add this web found information to my tree, but I want the information I add to be my family and I want it sourced. Yes, it takes longer, but at least I know that when I share my information is valid. And I agree again with Cynthia the longer you take with each person you research they become more than just name they are family.
CD
Cynthia Dooley

17 years ago

How true! There are so many people out there who want to make a tree anyway they can, just to complete the project. Those are the people who will send out undocumented data, because they found a surname that was the same or similar to the one they were searching. Any time I receive new information, I start looking for something to document the name, dates and locations. It would be very easy to just add this new information to my tree, but I don’t and won’t do that. It takes longer to build your tree, but when it’s done this way, you are certain it is your family. I also feel that I get to know this long ago person just a bit better. They become more then a name in my tree.