One of the common ways to apply polymorphism (and Information Expert) is in the context of what Peter Coad calls the “Do It Myself” strategy or pattern [Coad95]. That is:
Do It Myself
“I (a software object) do those things that are normally done to the actual object that I'm an abstraction of.” [Coad95]
This is the classic object-oriented design style: Circle objects draw themselves, Square objects draw themselves, Text objects spell-check themselves, and so forth.
Notice that a Text object spell-checking itself is an example of Information Expert: The object that has the information related to the work does it (a Dictionary is also a candidate, by Expert).
Do It Myself and Information ...