Teaching a new language in a course, when the language is not the focus of the course

Like many computer science departments, the languages we teach our students vary over time. When I was hired, we taught Java in Intro and C++ in Data Structures (our CS 2 course). The year I started, we moved to teaching Java in both Intro and Data Structures. (Thank god, because my C++ was pretty rusty at that point.) When I returned from maternity leave in 2008, we switched to Python in both Intro and Data Structures. This was absolutely the right move for Intro, as it’s much easier to get up and get going in Python than it is in Java, but proved a bit problematic for Data Structures—not right away, but down the road, as we found that our majors were less willing to learn new languages since Python was so easy and familiar to them, which in some cases really hurt their Comps (capstone) projects. (Image and sound processing in Python? Bad idea!)

A few years ago, we decided to keep Python in Intro, but switch Data Structures to Java. The switch had the intended effect—our majors are more comfortable learning new languages on the fly, because by the time they’ve finished their first 2 CS courses they’ve programmed in 2 languages. But of course we originally switched from Java for a reason—its steeper learning curve. (public static void main(String[] args), anyone?) And so we still run into the issue: how do you successfully introduce Java, or any new language, in an early CS course, when the language itself is secondary to the course?

I’ve taught the course twice now under this “new” format, and I think this time around things with the language transition went much, much better. There’s still a lot I can improve, for sure (more coding in front of the class instead of just giving them some code and setting them loose, more small examples at the beginning), but there were a few things that definitely went better this time around:

  • I spent a full 2 weeks just on Java. Even though this meant I had to cut down on some things I would normally cover (like my beloved Dijkstra’s algorithm, and some of the finer points of hash tables), I felt it was important to give the students enough time to become comfortable, or at least familiar, with the new language before asking them to dive into the course concepts AND implement them in the new language.
  • I started the language transition by providing examples in both Python and Java. I wanted my students to come away from the experience realizing that Python and Java really aren’t so different, and while Java definitely has more overhead, it also has a lot in common with Python. Showing the same code in both languages, and giving them both versions of the code to play with and modify, helped them be comfortable with thinking in the new language. In fact, in many of the early exercises, I encouraged students to write the code in Python first if they were confused, and then translate it into Java. (I also relied on readings that introduced Java syntax and principles in relation to Python: Brad Miller’s Java for Python Programmers, and Ken Lambert’s From Python to Java. The latter is great because it has the same concept presented with side-by-side code examples.)
  • I approached inheritance differently. Inheritance is a topic we all agree that students should be familiar with by the time they finish Data Structures. I used to stress inheritance quite a bit early on, having students write subclasses and interfaces and so on in an early project. This time around, we did some straightforward inheritance examples late in Week 2, with subclasses and superclasses, and discussed a bit about abstract classes, but I limited this largely to in-class exercises. Related to this…
  • I incorporated interfaces throughout the course, as “code templates”. Students find the idea of interfaces confusing, and rightly so. I decided this time around that I was ok if they didn’t fully understand what an interface was or the instances in which we might use one, as long as they could use and incorporate interfaces somewhat competently in their code. So for every ADT we studied, I gave them an interface for that ADT. I “sold” it as a template for what their methods should look like and how they should behave. I used it to illustrate that we can implement ADTs quite differently and they can still function the same way (and that the end user doesn’t have to and shouldn’t know anything about the inner workings of the resulting data structure). I don’t know how much students really understood about interfaces by the end of the term, but at least they were able to competently integrate them into their code. (Bonus: they made grading the projects much, much easier—everyone’s methods had the same signatures!)

There are still challenges when teaching the course in Java: how and when to introduce generics (I tend to minimize these: students can use them, but I don’t require them to implement classes with generics), finding a textbook that I can live with (still searching), etc. And surely as I continue to reflect on Winter Term as I gear up for Spring Term, I’ll remember more of what worked and what didn’t. But overall I’m pretty pleased with the language-related stuff in the course this time around, and will probably use largely the same model the next time I teach the course. (Assuming, of course, we don’t decide on another language switch between now and then….)


Leading in the midst of tragedy

On Saturday, the Saturday at the end of 8th week of winter term, our computer science seniors gathered to present their Comps (group capstone projects, for those readers outside of Carleton). The day typically has a celebratory feel: this is the culmination of 2 terms of hard work on their part, and this is their chance to present their work to their friends, family, and classmates. The morning started, as it usually does, with a welcome from the CS faculty, which this year I gave.

Except instead of welcoming the students, friends, and family like I normally would, I stood in front of all those gathered, with the rest of the CS faculty at my side, and tried to speak words that would make some sense at all of the tragic events of the day before: the loss of three students, including one of our junior majors, and the serious injuries to two other students.

Someone asked me later what I said. To be honest, I have no idea. The shock and grief were too much. I remember going to the front of the room and picking up a microphone (and then handing it off to one of our seniors when I couldn’t figure out how to turn it on). I remember talking, but not the actual words. I remember asking for a moment of silence. I remember thanking everyone. And the next thing I remember, I was sobbing in the ladies’ room.

Our students carried on admirably, given the circumstances. I think it helped that we were all together that day, as a department, and that we had something else to concentrate on for a while. It helped that we rearranged the schedule so that we could attend the memorial service in the middle of the day. But I’ll admit I was splitting my time between listening to the presentations and figuring out what we, as a department, should do: for our grieving students, for the family of Paxton, for each other.

There is nothing in the chair’s handbook that walks you through what to do as a department when a student passes away. There is nothing in the faculty handbook that indicates what you should do the first class meeting after a tragic event plunges a campus into grief, or how to counsel students who are struggling to make sense of something that makes no sense at all, who are grief-stricken and in shock and maybe feeling even more alone than before. There is nothing in my years of on-the-job experience that remotely prepares me for what I, as a faculty member and as a department chair, am dealing with now.

So I’m figuring things out as I go along. I didn’t plan any special remarks for class—I went with what I was thinking at the moment, and I honestly told my students that I wasn’t sure how to proceed, either, but that I would just try. That we’d be flexible and figure things out together and see where that left us. That it was important to reach out and to keep talking and to use the available campus resources. That I am also a resource that they can lean on, even if I don’t exactly know what I’m doing. That the next days and weeks and months would be sad and hard, but that we are a strong community and that ultimately that will get us through.

This afternoon and this evening, we will gather as a department to remember Paxton especially, but also James and Michael, and send healing thoughts to Will and Connor. It won’t be enough. It won’t be nearly enough. But it’s something, and we’ll figure out the rest as we go along.