Digital genealogy organizing project Intermission 2: Thoughts about an Ahnentafel folder structure for personal research

Although I am not yet finished with filing all the files in the previous step, I figured that some of you reading were already ready to move to the next step, namely, to structure your personal research folder.

Some of the people I talk to like to organize their personal research using an Ahnentafel numbering system. If you're unfamiliar with that system, let me briefly describe it. In such a system, you take the starting person for the personal research (usually yourself, but it could be a spouse or child if you are working on their ancestors instead) and assign them the number 1. You then number that person's father as number 2, and the first person's mother as number 3.

This continues such that the paternal grandfather is number 4, the paternal grandmother number 5, the maternal grandfather number 6, and the maternal grandmother number 7.

You may now realize that these numbers match the numbers you usually find on a published pedigree chart. However, these numbers would continue as far back as needed, and you can quickly generate the new numbers by doubling someone's number to get the number for their father, and adding one to that to get the number for their mother.

This numbering system can cause a bit of confusion if there is any documented pedigree collapse. In other words, the same people can appear on different lines of the ancestry. In short, at some point, cousins (at any distance) married cousins.  This means that the same people will have multiple Ahnentafel numbers. In this case, you normally use the lowest number available, and leave the others essentially blank.  Personally, I have not encountered this yet, at least not within my own documented ancestry, although this might eventually be a problem for me if I can link back to documented royal lines (where people certainly married their cousins).

So how might you organize your genealogy folders with this system? You could create a folder for each ancestral couple, starting with their pair of Ahnentafel numbers. Your parents would have a folder whose name would begin with 2-3 (followed by their names), your paternal grandparents would have a folder with a name starting 4-5, and so forth.

I also talk about this kind of system in my Organize Your Genealogy book (pages 84-87).  You can even see a photo on page 93 of an example of this kind of system used to organize hanging folders, but putting the Ahnentafel numbers at the end.

This would be a good time for me to mention that, in the book, I talk a bit about adding leading zeros to force the digital folders to sort in alphabetical sequence. At least, this is something you *had* to do prior to Windows XP or Mac OS X. But it was brought to my attention recently (thanks, Mike Scozzari!) that it is no longer necessary to artificially include leading zeros, because modern microcomputer operating systems use an "intuitive" sorting order, such that numbers in a file or folder name are treated as numbers instead of characters. So Ahnentafel number 2-3 will sort automatically before 10-11.  (Although this is probably helpful in most situations, this does upset some folks who want to treat numbers as characters and not numbers.)

Unfortunately, an Ahnentafel system has some drawbacks. For one thing, it is designed to work with ancestral research, not descendant research. It's fine for going from yourself backwards in time through your direct ancestors, but doesn't work nearly as well for collateral lines, and certainly not really at all with a research project that begins with a distant ancestor (say, an immigrant ancestor) and that then attempts to locate all known descendants. Yes, there are other numbering systems that are intended for numbering descendants, but almost all of these cause problems as soon as you identify a previously unknown descendant who isn't the youngest among their siblings. (Suddenly everyone else after them needs to be renumbered.)

The other drawback is that it means that your folders jump around from one side of your family to another, instead of all closely related families being somewhat closely filed.

Who should still use an Ahnentafel folder numbering system? Perhaps those who are just getting started, and working on a beginner's project, such as identifying the 8 great-great-grandparents, or taking a single surname line all the way back in time.  But it's not currently my favorite for more complex ancestral projects or for descendant projects. What would work better? Let's see...