When you begin investigating your ancestry in today[s world, you are soon introduced into the confusing and overwhelmingly large pool of online family trees. One of the concepts that newly minted family historians have to grapple with is the reliability or accuracy of the information presented in the millions of online family trees. It is overly simplistic to merely assume their validity, but on the other hand, how do you know whether or not the information presented is accurate or inaccurate?
One of first crisis events in a new researcher's life is when they discover that their respected elderly ancestors were sometimes sloppy and inaccurate in their family history records. On the other hand, it is way too facile to dismiss inherited information as unreliable merely because it is old and lacks source citations. But it also a mistake to assume that merely because your ancestor recorded the information from personal knowledge that the information is correct. There are many instances where people's memories were faulty or even situations where they lied about the facts and dates.
Fortunately, there are some methods of detecting errors and some common indicators that what is recorded is likely to be wrong. However, carried to an extreme, you may end up like me, categorically disbelieving almost any unverified fact or event claimed by an ancestor.
Over my long years of examining family records from a huge variety of sources, I have evolved my own strategy for evaluating family information. I will use the FamilySearch.org Family Tree as my primary example of how I evaluate the information. I do this because the Family Tree is a compilation of over 100 years' worth of records and does a good job of illustrating both the good and the bad aspects of what has been accumulated.
It is extremely easy today to "copy" someone's family tree in its entirety. We often assume that the proliferation of online family trees is primarily derived from the mindless and uncritical copying of family trees accumulated by a very few "true" researchers. However, the true situation is much more complicated than this simplistic explanation would seem to indicate. Especially with the FamilySearch.org Family Tree, the information is a composite and not necessarily the result of copied information. To the extent that some information was "copied" from generation to generation in the Church, there are likely some errors that were reproduced, but most of the inconsistencies and errors in the tree are more attributable to previous issues of methodology and lack of current verification from valid source records or documents.
Here are some examples with commentary on the types of errors that exist and how they affect the determination of accuracy on the part of a user of the Family Tree program. The first is a daughter listed with William Stewart (b. 1740, d. 1826) and Amy Huntington (b. 1751, d. 1839).
This is a prime example of incomplete and probably inaccurate information. If your family has been submitting information to FamilySearch and its predecessors for some time, you can undoubtedly go back on some family lines until you reach a relative or ancestor with this type of information. The giveaway here is that the birth place is still in abbreviations. This means essentially that no one has work on updating the information or standardizing the place names. This situation is a flag to me that the entry is really speculation and not verified.
There are no sources listed for this person so any verification of the information will require research. The effect of having a person like this in your family tree, whether it be the FamilySearch.org Family Tree or in another program, is that you have no basis for either relying on the accuracy of the entry or doing additional research on this person's ancestors.
It would seem that all of this information is derived or calculated from some sort of early record. What is the main problem is that by being formatted in this fashion with an "of" as part of the place, the Family Tree program probably be unable to provide any record hints. My best guess for this person is that she is not the daughter of of William and Amy Stewart but a person named Content Douglass who married a Samuel Stewart. Unfortunately, this family is out in the New England part of the Family Tree that cannot be fixed until the Family Tree is separated from new.FamilySearch.org.
Next is an example that is a little more complicated but essentially the same.
The death information seems to be specific and complete, but the birth information is just a vague as the previous record but in this case, there is a reference to a marriage record and two legacy new.FamilySearch.org sources. The marriage date is likely accurate and is supported by the citation to a marriage source. The two things that catch my attention are the lack of a complete middle name and the "Abt" designation for the date. It is acceptable to estimate dates and give the best place found, but when this is done, it is customary to be aware that the information may not be accurate and could be misleading. There are four sources cited but none of them confirm a birth date or place.
The next example is another classic case of misinformation personified.
This appears to be a valid entry except for the fact that there are no sources cited and the fact that Rhode Island was first settled by Roger Williams in 1636 so it would have been difficult for Francis Tanner to be born in a place that did not exist at the time. This is a particularly common problem with locations that turn out not to exist at the time the event is supposed to have happened. If the documents tend to show that the person did exist, then the dates may simply be wrong. But in this case the information here is used to add additional generations.
The key here is to take the time to examine the entries and think about what they say. If there are sources, do they support the dates and places or merely take up space.