The word “atom” comes from the Greek atomos, meaning indivisible. Merriam Webster defines it as “the smallest particle of a substance that can exist by itself” or “a very small amount of something.”
When it comes to doing genealogy, I define atomic genealogy as answering the question, “Is person X in record A the same as person Y in record B?” In other words, “Do these two records talk about the same person?”
The conclusion resulting from an atomic operation is itself, a record. In other words, the entry for your James Smith in FamilySearch Family Tree is a record. When you find a historic record about a James Smith, the decision that the historic record is about your James Smith is atomic genealogy.
I believe this census record about James Smith should be attached to this James Smith in the tree because they have the same name, the approximate birth year from the census (1879) matches the birth date in the tree (2 June 1880), the wives’ names are the same (Mary), and the names and ages of the three children in the census household (Susan, David, and Tom) match three of his five children in the tree (Susan, David, and Thomas).
When Family Tree asks for your reason for attaching the record to the tree, do you enter all this? Or is it all self-evident? Keep in mind that after you attach the record, the values in the tree might change. Is your time better spent otherwise? I’ve been told that most people leave the reason blank. Is that okay?
What do you think?