By selecting a language (or a couple of languges) they are trying to make it easier to focus on the concepts. Its hard to focus on the fundamentals when you hav

By selecting a language (or a couple of languges) they are trying to make it easier to focus on the concepts. Its hard to focus on the fundamentals when you have too keep looking up basic syntax. By limiting the number of languages they spend less time doing trivial projects, and more time focusing on new content. On the flip side letting students only use their favorite language (as they might if teachers select the language used without guidelines), then you get students who are far from language agnostic (i.e. inflexible). Many would respond that learning a new language is trivial. And it is trivial to learn most of the syntax of a new language, but it is not necessarily trivial to set up a good programming environment (setting up slime and SBCL the first time threw me for a loop, things kept not quite working and had to be tracked down), nor is learning syntax the hardest part of learning a language. I find that the longest and most difficult component of language learning is learning which libraries contain which functionality, and the language specific idioms.