Speaking as your brother, the thing that tipped me onto the preconceptions thing was the odd student who, with no prior programming experience, declared "oh, I get it. It's just maths!"
I was the TA on the Edinburgh Haskell course over a couple of years, and took the attitude that, whether the students are any good at maths, they've at least seen it before, and so it was something I could use to bootstrap their understanding of the code they wrote.
The Edinburgh course is very nicely paced. Students aren't thrown in at the deep-end. In the first tutorial we had them composing pictures along similar lines to that shown in the OP. By the third tutorial, they're using their repertoire of maps, filters and folds to do basic web scraping. The most advanced stuff we assess them on is writing recursive functions on recursive data-types, like a function that takes a simple mathematical expression and evaluates it. Come the final exam, they can pretend they'd never heard the word "monad."
I was the TA on the Edinburgh Haskell course over a couple of years, and took the attitude that, whether the students are any good at maths, they've at least seen it before, and so it was something I could use to bootstrap their understanding of the code they wrote.
The Edinburgh course is very nicely paced. Students aren't thrown in at the deep-end. In the first tutorial we had them composing pictures along similar lines to that shown in the OP. By the third tutorial, they're using their repertoire of maps, filters and folds to do basic web scraping. The most advanced stuff we assess them on is writing recursive functions on recursive data-types, like a function that takes a simple mathematical expression and evaluates it. Come the final exam, they can pretend they'd never heard the word "monad."