Four Surgeons

Four surgeons were taking a coffee break and were discussing their work.
The first said, "I think accountants are the easiest to operate on. You open them up and everything inside is numbered."
The second said, "I think librarians are the easiest to operate on. You open them up and everything inside is in alphabetical order."
The third said, "I like to operate on electricians. You open them up and everything inside is color-coded."
The fourth surgeon said, "I like technicians...they always understand when you have a few parts left over at the end..."