Kim Bruce, statement, CS2 workshop

First some ruminations on traditional CS2 topics:

• The availability of good libraries has changed the way programming is actually done (at last!) from the emphasis of putting together many lines of low-level code to the integration of systems of objects.

• Because of the existence of these libraries (esp. OO), it no longer makes sense to ask students to write implementations of all the data structures from scratch.

• One of Murphy's laws is that no matter what you have available, what you need will be slightly different, so students need to know how to adapt existing classes and how to write data structures and algorithms from scratch (though we don't need to devote as much time to do this as we did earlier).

• Trade-offs are still at the heart of much CS. Students must be aware that there are different ways of doing things, e.g., different implementations of data structures and different algorithms for solving problems. They need to know how to analyze these alternative ways of doing things and to know how to choose the best ones for the current problem.

There are also some new things that we should be thinking about:

• Event-driven programming is an important way of thinking and students should understand how this works as well as how it is done in high-level languages. GUI's and active components are also important today and form a good model for event-driven programming. We can protect students in the early years of much of the tedium of designing good user-interfaces while giving them experience in programming to them. From a public-relations point of view, programming to GUI's is also much more interesting for students.

• Concurrency is no longer an exotic technique. It makes some things much easier, but also throws in unexpected difficulties. Concurrency should be introduced into the curriculum early (perhaps even in CS 1), while pushing off more complex aspects to more advanced courses.

• OO design is hard - in my opinion harder than traditional structured programming - though the rewards for a good design are much higher. We need to start introducing students to the elements of OO design. Patterns can certainly be part of this, but there are more fundamental issues as well. We can't expect students to just absorb this material on their own.