Regarding advantages for learning, via introducing concepts incrementally, Haskell has its own strengths over Scheme as well as vice-versa. You can start on bot

Regarding advantages for learning, via introducing concepts incrementally, Haskell has its own strengths over Scheme as well as vice-versa. You can start on both with "the interactive interpreter is a calculator!", and introduce the non-numeric data types -- but then, in Haskell, you can bring in the various monads to introduce other paradigms. For instance: once the students have a handle on pure code, show them State for, well, state; Maybe/Either for exception handling; Writer for output; lists for prolog-esque non-determinism; ST for a richer model of mutable state; and finally IO for side-effects. Also, I guess I like "getting them while they're young" when it comes to static typing -- it encourages a certain rigour of thought that I feel serves me well even in dynamically typed langauges.