Over the years, I keep hearing huge numbers from people working on their family trees. This is not too surprising given that the basic numerical progression of ancestors is exponential. But some of the numbers are quite unbelievable, over 100,000 or even two or three times that much. My great-grandmother worked on her and her husband's ancestry for about 30 years. I inherited her "files" which, of course, were all on paper. Working pretty steadily, it took me almost 10 years to transcribe all her research and enter it into a succession of computer programs. In the end, she had accumulated just over 16,000 names. But this large number had been accomplished mainly through name extraction. In other words, she copied out anyone in a particular parish or area with the same surname as the people she was searching for. In other instances, with research on my family lines, I found that other relatives, not my great-grandmother, had followed some pedigree lines through convenience, assuming a relationship to the most promising ancestor rather than making the hard choice to admit that they had no more evidence.
Those experiences, finding that many of the people in her files were not remotely related to my family, the unsubstantiated family lines of other relatives and my subsequent experiences in working with people and their online family trees, has helped to make me somewhat skeptical of very large genealogy files.
I am personally acquainted with several people who are doing the same type of name extraction as my great-grandmother did, only on a much larger scale. Don't get me wrong, my great-grandmother did a huge amount of valid and documented genealogical research considering the time and effort it took to do research by mail and with the limited resources she had. I am forever indebted to her for her magnificent work. But what I see today, involves copying on a massive scale. My great-grandmother had a very valid reason for doing what she did. The documentary evidence she had was scanty to say the least. Every so often, she would find a distant relative that was able to connect a little more the family.
Not infrequently, as I pursued the work previously done on my family lines, I found, as I already mentioned, where researchers had done essentially the same thing over and over. Chosen an ancestor, let's say at random, merely because there was a "documented" pedigree for that person or because the surname was the same. It is also interesting that many of those pedigrees involved some sort of Welsh or English royalty. I never yet found one of these lines that could be documented. Now, I find the same type of suppositional work in many of the larger online family tree files. I have written several times before how many wrong people have been connected to my ancestors in FamilySearch.org Family Tree. This is the case even when good, reliable documentary evidence is not only available, but easily obtained.
So my basic approach to very large files is skepticism. I am reasonably sure that there are many of the owners of these huge files that would defend every last name as absolutely verified and reliable. Perhaps, that is where we part company. I am never sure about anything in my file. I have personally verified lines that go back quite a ways, but in every single case, the line has "ended" in obscurity and conflicting evidence. I have had people come to me and declare that they have "solved" the mystery of the arrival of my ancestor in America, only to ignore me when I requested the sources for the evidence they claimed to have. Many of the lengthy pedigrees I found in relatives research we very easily proved to be unsustainable and without foundation.
I have no response to those who claim ancestry back to some remote and famous person. I have spent too many hours trying to "help" someone prove that they were related to those same famous people and who refused to acknowledge my doubts that the relationship they claimed was not based in fact.
Now, I fully understand that famous people and European Royalty had children and that there are people who are related to some of them. Given the reality of pedigree collapse, it is not only possible, but highly likely that many of us Americans are related to some royal person or another. My skepticism arises from the practice of then "adopting" that royal person's pedigree without question.
In addition, if I chose to incorporate every person in every family tree that the large companies tell me I am related to, I too would also have hundreds of thousands of names in my file.
Every time I raise this subject in any context, I am immediately attacked by someone who claims the every single name in his or her file was put there one by one through their sweat and blood. In those circumstances I defer. But the question really is what do you do with all those names? I am finding it difficult to compile documentation after a reasonably exhaustive search for only a limited number of generations of my own verified ancestors. A job, by the way, of documenting sources that has not been done previously. If I were to go into the Family Tree program or any other family tree program, I would find the same situation. I would find that there was little or no documentation for the names in the trees. So you must excuse me one more time for my skepticism. Perhaps that also came from my many years of listening to my law clients and their opponents.
When I am sincerely asked what to do about a large file inherited from a relative, I always give the same answer. Begin to verify and add sources to the file. You may find, like I did, that some severe pruning is in order.