Proper Struggle Preparation

Posted on April 4, 2014


Yesterday’s lecture in Java II was, I think, an excellent example of When It Would Be Wrong To Make People Struggle (and he didn’t).  

We’re learning about exceptions, a.k.a. errors in programs.   Essentially, this is a fairly complex set of ideas that, if put together nicely, hang together well.   If not, things don’t work.

So first there is the idea that “exceptions” are more complicated than “errors,” and that there are assorted kinds.  Our first experience was to ask a user to enter numbers, which we would then translate into units of currency (so 36.77 would be three ten dollar bills, a five dollar bill…)   — so a little bit of fun working out the division and modulus things there — and we keep prompting for numbers until the person enters “quit.”  

   But what if the person enters “hello?”   We had to figure out how to detect that, and type a message and have the person try again.  

   Yes, there were things to figure out — but we were applying a very simple framework for the exception; the new stuff is uncomplicated.

Yesterday’s lecture went on to creating our own — and lots of language connecting between “try, catch, throw” and what is happening in the program, what isn’t happening, and when.   We walked through exactly the same metaphorical visualization… which meant I could nail it down, hopefully firmly.   (For the record, and memorize key phrases, yes. An exception thrown but not caught still ends the program. Some of us *do* memorize on the way to understanding.)  

Lab 9 will integrate a mess of stuff we’ve been doing this year … with what seems like will be a simply structured “exception.”   I shall struggle gamely with the integration — but struggle with the stuff that I’ve already made sense of in isolation, so it’s ready for the challenge of integration. 

Riding in this morning, it occurred to me that concepts like exponents could be handled this way.   Let’s *build* that idea of going to two and three dimensions… and then dont’ assume that because we’ve explained it once, it’s in there.   Let’s show the pictures of squares and cubes oh, every time it comes up for a while. Let’s also make sure it comes up — in reasonably simple form — here, there, and everywhere. And … let me hopefully figure out this week’s “how to draw in Android” without too horrible much struggle because then I can do the same with my integer subtraction app.  Reckon it’s time to tackle 😉  

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