Big Complicated Programming Projects

Ria Galanos has a wonderful blog about her experiences moving from the classroom to a life as a professional software developer. It’s been a long time since I developed software for a living and her posts are bringing a lot of memories back. A recent post (Putting It All Together) talks about understanding a large code base. This is something professionals have to do often. They very seldom write code from scratch. usually they work enhancing, correcting, modifying, or otherwise working with large existing code bases. Understanding these complex  Ria talks about the Advanced Placement Computer Science A course which used to have a case study, a larger piece of code that students had to learn, understand, and modify. She wonders if bring that back might be a good idea to better prepare students for industry.

There are some interesting comments from experienced educators on that post. Mike Zamansky posted a follow up post (Big Code And Case Studies) where he talks in favor of large projects at the right time and that AP CS A might not be the right place for the type of case study required.  or at least not a specific and mandated case study that everyone uses.

We’re not trying to turn out professional software developers in high school. That is important to remember. There is a lot of value in learning how to understand large code bases though. I think there is value in it even for someone not planning on becoming a professional software developer.

So much of how we teach beginners lacks context. We focus on little bits is a sort of isolation. The projects we assign are simple and small. In some regards they have to be. The problem is that without real context understanding how things fit together is limited.

I’ve tried a number of things to give students involved in larger projects. I have given students larger, more complicated projects written by others. There are any number of professionally developed “samples” that are more complicated than the average beginner will write alone. I’ve also tried having students work in teams with different modules assigned to different students in the team. I’ve seen mixed results with both.

The trouble with large samples is that there is limited time to understand the code by the time students have enough base knowledge in a single semester course. Similarly in a one semester course there are limits to how complex a project student or group of students can build before time runs out.  APCSA is usually taught as a year long course and would seem to lend itself to either of these ideas, and the case study was a larger code base, there are still a lot of concepts required by the curriculum that can place time limits with some student bodies. This is especially the case when APCS A is a first course.

I’m starting to think that high schools need a sort of CS capstone course to follow up after AP CS or other foundational courses. Not ever student will have schedule room but I think that a lot of students who really fall in love with CS will find a way. Some schools will (or at least could) build at sequence that would include such a course. This course would allow students either individually or in a small group spend a whole semester (a year maybe) developing one large project. I think this could be a chance for students to work on learning a new (to them especially) technology.