Do we need to know every detail in a novel?

Here is an interesting question, and test, for all you writers out there. Do we really need to know every detail of a story to enjoy it? Do we have to know what color eyes or hair your character has? How about their age? Do we even have to know that to enjoy the story?

Let's start with the color of the eyes. Here is where the test begins: In the first chapter of the Wizard of Oz, what color are Dorothy's eyes? Stump you? Or did you snicker and point out that the first chapter is wrote to be all gray in everything? Okay, trick question, lets move on to chapter two, where everything is described in color - what color are Dorothy's eyes? Come on, you can get this one, can't you? Okay, how about a hint - Wizard of Oz. What? You say you read both chapter one and two and don't see any mention of Dorothy's eye color? Hmm... How about the color of her hair? Or an easy one - her age. Tell me how old she is.

Oh dear, he did not leave those details out, did he? How could he write a novel and not tell us such vital things? His novel will never sell. It will be scorned as not being worthy of being published... oh, yeah, I guess that's not true, huh? The Wizard of Oz survived such vagrant errors as not telling us what color Dorothy's eyes are, or her hair color, why, he even left her age out and the book does not seem to have been hurt any for such errors.

It would seem that you can leave details out and not have your book crumble around you. In the start of chapter one it was important for the reader to get a sense for how dreary live in Kansas was for Dorothy. Everything was gray, only her little dog had any color and he was all black.

For the same reason details were needed in chapter two. Not of Dorothy's sudden vibrant technicolor, but for the change in how she perceived the Munchkins. All colorful and her size. They were adults, but they were not someone who stood over her looking down on her as a child.

Picking the right details can make a huge difference. We would not have been as captivated by Oz if Dorothy had woke looking at the blue of her gingham checkered dress and the pink of her bonnet - instead those colors are not seen until after she has completed her encounter with the Munchkins and is getting ready to set out on the yellow brick road.

The power is in the details. In what you show and what you hold back.