Citing sources is one of those things in genealogy research that tends to make us kind of kind of twitchy. We know we should be doing it and we want to do them right... so we tend to stress out about it. But there is a key to thinking about citing sources—and it won't raise our blood pressure.
Why Do We Need to Bother With Citing Sources?
Citing sources isn't just for professional genealogists. Even if you are the only one who will ever see your research, you should cite where you found things.
It will help you go back to where you found specific pieces of information. (I have a hard time remembering what I had for dinner last night, let alone where I found information about my third-great-grandfather's death date.)
Citing your sources will help you with that cousin who has something wrong in their family tree. Asking them to change it "because I said so" usually isn't met with much success. Having good source citations to back you up will help your case. (They still might not change their tree, but your odds are better.)
Citing sources is also crucial for analysis. When (not if) you find conflicting information, you will need to know where you got the information. Only then will you be able to piece together which is correct.
Why So Stressed?
I think a lot of the stress we feel with source citations is that we don't quite know what it is we're supposed to cite, especially when we're dealing with online resources.
I'm a firm believer that if we have the elements that we need, we can always change the formatting later. The first thing is to be clear on what you need to cite.
The Key to Remember When Citing Sources
The key to remember when citing genealogy sources is to cite what you see.
Let's say that I use a book by Mary Smith that contains abstracts of marriage records in XYZ County Probate Court and I find my ancestors in there and it says their marriage record is in XYZ County Marriage Book A, page 123. What do I cite?
In this case, I need to cite Mary Smith's book. That's what I actually used. I didn't use the marriage records at the Probate Court, so I shouldn't cite that. (What I can do is add a note to my citation of Mary Smith's book to say that it references XYZ County Marriage Book A, page 123. It's a heads up that I should go look for that record.)
Databases (without images) are the same way. If I use the database "Hendricks County, Indiana Marriages (1902-1964)" on website of The Genealogy Center at the Allen County Public Library, I need to cite that as my source. I shouldn't cite the marriage record at the courthouse, because I haven't actually used it.
When I go to the Hendricks County Clerk's office and see that marriage record, then I can cite the original record.
What About Citing Digital Images?
What if instead of going to the Hendricks County Clerk, I went to FamilySearch and found a digital image of Sarah and Samuel's marriage record? How do I cite that?
In this case, it's a two-part citation (or a "layered" citation, as Elizabeth Shown Mills calls it). We want to cite the image because actually saw it. But we also need to make it clear that we didn't see the record in person; we only saw a digital image of it. We need to tell where we found it.
The first part of the citation would be along the lines of "Marriage record of Samuel L. Bartlett and Sarah C. Roberts, Hendricks County, Indiana marriage book 13, page 26."
The second part of the citation would indicate where we found the image. Something like, "digital image viewed [or downloaded] from "Indiana Marriages, 1811-2007', FamilySearch.org."
Be sure to include the name of the collection within FamilySearch (or Ancestry, MyHeritage, or whatever website you're using).
Cite What You See
The basic reason for a source citation is to point us (or someone else) back to where we found information. The only way we can do that accurately is to cite what we actually used. If we used a book, we cite the book; we don't make it look like we examined something else. The same goes with a database. We don't make it seem like we went to the courthouse and looked at the record.
Digital images are the same way—we cite the image (because we actually saw it) but we include where we found that image. That way, we are able to tell exactly where we found it.