Genealogy is often a mystery. Everyone loves a good mystery, right? In genealogy we want to solve all the mysteries and end up with all the facts. But until we do we need to search out the facts like any good detective.
The tools of a genealogy detective are very much like those of a good reporter. We want to know all the facts. We want to know the source of all the facts so we can evaluate their validity. "Anonymous sources" and those "highly placed sources" aren't good in genealogy. A good genealogist deals in documented facts.
Let's take the picture below. Who is it? It is Eliza Sciota Harding, known to her friends as Lida. Hopefully it says that on the back of the picture but most likely it doesn't. The picture's owner knew who it was and likely didn't see the need to write it on the picture. The owner never dreamed we'd be studying it 130 years later. We know it is Lida because we compared it to other pictures of Lida and recognized her, not to mention there were living folks who had known her when we first found the picture. In this case it was easy.
What is it? It's a picture. Did you think this was a trick question? That was the easy one.
When was it taken? This is harder. It can important in identifying who is in the picture. There are books which tell you what to look for in terms of backgrounds, poses, clothing, etc. If you have a lot of pictures to identify invest in a good book or two.
Lida isn't terribly old in this picture. How old do you think she is? Can you see that "I don't want to do this" look on her face? That, her childish body and her shorter skirt are indications of her age. Let's say she is 10. Since we know she was born in June 1869, if she is in fact 10 in the picture, this could have been taken between June 1879 and June 1880. It was probably taken in the winter because farmers didn't take time out for such things in the summer when every hour was devoted to work. We know her father was a farmer.
Where was it taken? Perhaps the name and town of the photographer is on the picture or the picture enclosure. In this case she was born, lived and died in a six mile area of the same county so we can be pretty sure it was taken in Logan County, Illinois.
Why isn't a critical question in this case. We have other pictures which would indicate all of the family members, Lida, her sister, her three brothers and her mother had their pictures taken at what appears to be the same time, same studio, same backgrounds. What about her father? If his picture was taken it did not survive. If there was a family portrait made it did not survive. The father, Benjamin Harding, appears in later family portraits so he wasn't against having his picture made. Probably his picture was taken when this one was but for some reason did not survive.