Did you notice small bumps on the F and J keys on a computer keyboard?? Wonder why they are a part of keyboard design.
Actually, the small bumps or ridges found on the F and J keys on a computer keyboard are to help the users to correctly position their left and right hands without having to look at the keyboard. The middle row is called the home row key position. Once you place your left and right index fingers on the F and J keys, accessing the remaining keyboard becomes easy.