Each weekly problem set consists of two pieces: a set of drill
exercises from the text book and a set of required
exercises. Some of the required exercises are project
exercises; you will only get the full benefit of the course by
solving all of those project exercises and maintaining their solutions
over the entire course.
The drill exercises are recommended so that you understand the ideas from
the weekly readings. Solving this problems---in DrScheme, not just on
paper and pencil---will give you the required fluency in "the HtDP
teaching languages" to solve the required exercises. Think of them as
guide posts on the recommended path through the book.
The required exercises are those that you turn in. During the first lab,
you will receive instructions on how to submit this required exercises via
the Subversion server.