A capital mistake

In the book, The Adventures of Sherlock Holmes by Sir Arthur Conan Doyle, in a story called "A Scandal in Bohemia," Holmes in responding to a question from Doctor Watson says, "I have no data yet. It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts." See Doyle, Arthur Conan, and Sidney Paget. The Adventures of Sherlock Holmes. London: G. Newnes, 1892. and about a hundred editions since then.

It is very easy to jump to conclusions and it is not so easy to jump back. I find that genealogical researchers are often prone to make unwarranted conclusions from very little data. For example, it is common to conclude because only a certain number of children are listed in the U.S. Census records that there were no more children in the family. If you make this unwarranted assumption, you will almost always miss a child who was born after one Census and died before the next. You will also miss any children who may have been living in some other household at the time of the Census. In one of the U.S. Census records for my Great-grandfather, there is an additional child with the same surname listed who is not a child of my Great-grandfather and his wife. Obviously, if this person was living with my Great-grandfather's family at the time of the Census, this person may not have been listed in his own family. Sometimes families that seem to vanish from the Census records are really there but living in some other household where their surname was recorded incorrectly.

I am frequently asked why I continue to gather documents about my ancestors when I already know the minimum vital record information, birth, death, marriage etc? The answer is simple, you cannot know too many facts about your family. You may just be surprised to learn of an undiscovered family member or solve some other unexpected mystery.

As Holmes says, it is most serious to begin to draw conclusions from limited data. A question of relationship, especially parentage, is not solved until there is sufficient evidence to support no other theory. That does not mean that you should not use the data you collect to support further research, it merely means that you do not draw conclusions until the evidence is there to support the conclusion.

When a jury is instructed by a judge during the course of a criminal trial, the judge will almost always give the following jury instruction or something similar to it:

You will decide what the facts are from the evidence that will be presented in this courtroom. That evidence will consist of the testimony of witnesses, documents and other material admitted into evidence as exhibits, and any facts on which the lawyers agree or that I may instruct you to accept.
The following are not evidence and you must not consider them as evidence in deciding the facts of this case:

• statements and arguments by the attorneys,
• questions and objections of the attorneys, and
• testimony that I instruct you to disregard.

There are two kinds of evidence: direct and circumstantial. Direct evidence is testimony by a witness about what that witness personally saw or heard or did. Circumstantial evidence is indirect evidence; that is, it is evidence from which you can infer another fact. As an example: if you wake up in the morning and see that the sidewalk is wet, you may infer that it rained during the night. The wet sidewalk is circumstantial evidence that it rained. Other evidence, however, may provide another explanation for the water on the sidewalk, such as a garden hose that was left on overnight. Therefore, before you decide that a fact has been proved by circumstantial evidence, you must consider all the evidence in the light of reason, experience and common sense.
In deciding this case, you may consider both direct and circumstantial evidence. The law permits you to give equal weight to both, but it is for you to decide how much weight to give to any evidence.
Some evidence may be admitted for a limited purpose only. When I instruct you that a piece of evidence has been admitted for a limited purpose, you must consider it only for that purpose and for no other.

It is a good idea to use the same kind of standard when considering your own genealogical evidence. If you do not have complete documentation of a fact, remain skeptical until the issue is resolved by competent evidence.