Find what kind of tree?

when i was in a botany class we had this book that let me find out what the scientific name of a plant was. through a process of elimination. (like is the leaf smooth edge - go to question 4; is the leaf lobed - go to question 10; something like that)

this book would ask all kinds of questions like how many leaves grow on the stock, what the flower looks like, if there is on. is there any fruit.

and through a process of elimination you end up with the scientific name of the plant.

My questions is what is the process call and is there an online one that I could use to identify some trees that are in my yard.

thank you

Find what kind of tree?
It's called a dichotomous key. There are a few online keys, but without knowing your region I can't recommend one. Not to mention the trees in your yard may be ornamental and not in a field guide to your area.

If you're on the US west coast, I recommend getting "Pacific Coast Trees" out of the library; it's got native and exotic trees commonly found in CA, OR, and WA.

I'd recommend taking some photos and posting on Answers, or getting a book out of the library. I haven't seen many good keys online.