Family researchers usually research events long after they have happened. That makes genealogy research different, particularly when all the participants in an event are deceased. When researching information about the birth of an ancestor in 1823, the parents cannot be talked to, the child cannot be talked to, contemporaries of the person cannot be talked to. We are left with whatever records were created that reference the event and that survived to the present day. The evidence that makes its way to us is not necessarily the most accurate and not the most complete. It’s what had the best preservation or was fortunate enough not to be destroyed.
That’s why it’s important obtain as many sources as possible and determine their reliability as best we can.
And…genealogy research is not like a modern scientific study. We can’t just “run a new test” or “conduct a new survey or study” to see what happens.