Comment by dspillett

> divergence between what's taught in school and in practice

I remember this sort of thing being mentioned but not in as much detail as I would have gone into (though I'd self-taught a lot of this before Uni, so for me it was more an exercise in unlearning mistakes and formalising & rounding off knowledge than it was about taking in new concepts, perhaps for others cramming the extra detail in would have been counter productive). Algorithm courses would say things like "of course caching methods should be taking into consideration, you'll cover this in architecture modules" and architecture modules would say "you'll cover the effect on some algorithms in much more detail in your software engineering modules"!

All the JS sorting demos that were an active fad a short while ago were simplified in the same way: they assumed that either a comparison or a swap was always the most expensive operation and the other can be discounted, or that all swaps/comparisons are equal due to uniform memory speed (no accounting for caching), and no consideration was made for what was being sorted (inserts are much more expensive in an array than a linked list for instance). I keep meaning to find the time to put a less superficial demo together that allows such things to be modelled at a basic level, perhaps even trying to illustrate the effect of a more distributed architecture (where there is more than one processing unit involved and everything isn't in local fast memory).

Of course, for the most part these simplifications are perfectly valid, but they should always carry a caveat noting what simplifying assumptions are being applied so people learning know that the issues could be more complicated so some critical thinking should be applied in any real world situation.