Teach two languages if you have to: Balancing ease of learning and learning objectives

My most recent CACM Blog post addresses a common question in computer science education: Should we teach two programming languages in a course to encourage abstraction, or just one? Does it hurt students to teach two? Does it help them to learn a second language earlier? My answer (in really short form) is “Just teach one, because it takes longer to learn one than you expect. If you teach two or more, students are going to struggle to develop deep understanding.”

But if your learning objective is for students to learn two (or more languages), teach two or more languages. You’re going to have to pay the piper sometime. Delaying is better, because it’s easier and more effective to transfer deep knowledge than to try to transfer surface-level representations.

The issue is like the question of recursion-first or iterative-control-structures-first. (See this earlier blog post.) If your students don’t have to learn iterative control structures, then teach recursion-only. Recursion is easier and more flexible. But if you have to teach both, teach iteration first. Yes, iteration is hard, and learning iteration-first makes recursion harder to learn later, but if you have to do it, iteration-first is the better order.

There’s a lot we know about making computing easier to learn. But sometimes, we just can’t use it, because there are external forces that require certain learning objectives.

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I correct, continue, and explore tangents on this blog post here: https://computinged.wordpress.com/2018/06/15/are-you-talking-to-me-interaction-between-teachers-and-researchers-around-evidence-truth-and-decision-making/