6 ms·

IMO the problem with object-oriented programming is that it turned into the standard curriculum for peoples' first semester of computer science, rather than bei

by lacker 10y ago

IMO the problem with object-oriented programming is that it turned into the standard curriculum for peoples' first semester of computer science, rather than being yet another interesting concept that advanced programmers would ponder. And the way we handle "the standard CS curriculum" sucks. (In the USA at least.) For example, AP Computer Science requires Java and tries to teach stuff like designing inheritance hierarchies to people in their first two months of programming education. And then tests it mostly using multiple-choice quizzes. It's totally inappropriate - most of these students would fail fizzbuzz. OOP should be something you only get into after you have written some practical programs, rather than something where you can't program, but you memorize the difference between "is-a" and "has-a" inheritance so that you can pass multiple choice tests.

stevedonovan 10y ago
OOP made sense to people who already knew structured programming and understood functional decomposition (what we now call 'refactoring'). Perhaps education should start with that and then justify OOP? I remember reading about the original LOGO experiments; one thing kids do not spontaneously do is break up their monolithic actions into sensible functions.
- lacker 10y ago
  Yeah "breaking up a complex function into simpler functions" is a great example of something that isn't taught well today, yet is simpler and more critical than what we try to teach people in intro courses. I think of it in analogy to math. OOP is like topology - it's definitely useful in some cases, it's not too hard for an experienced mathematician to get the basics, and yet in a lot of situations it's irrelevant and it doesn't really belong in the first class you take. Being able to solve fizzbuzz is like doing arithmetic. If you can't solve fizzbuzz then you aren't going to be able to really get any advanced concepts. It's like you can't be a good mathematician if you can't figure out whether 351 is an odd number - you need to learn the basics first, even if "real math isn't about arithmetic". Sadly, you can tell if you do a lot of phone screens that many people who graduate with CS degrees still can't code fizzbuzz. Our CS education is busted right at the beginning. It needs to get the basics right, like, can you write loops, can you write functions. Today it is failing at that.
  - mercer 10y ago
    Perhaps inheritance is easier to teach, which might be completely unrelated to how useful it is in practice? That would explain a lot. It reminds me a bit of how I was taught basic economics, where societies go from barter to currency. Apparently this is not true at all, but it's a story that is easy to teach.
- TickleSteve 10y ago
  Functional decomposition != refactoring. They are two completely different processes. https://en.wikipedia.org/wiki/Functional_decomposition https://en.wikipedia.org/wiki/Functional_decomposition https://en.wikipedia.org/wiki/Code_refactoring https://en.wikipedia.org/wiki/Code_refactoring
  - emsy 10y ago
    Breaking up a large functions into smaller functions isn't even (strictly speaking) functional decomposition because not every sub-function might be dependent on the previous function. "Extract function" is a kind of refactoring, but not refactoring itself.
- shrugger 10y ago
  That is exactly true! I have experience teaching kids Lua, and with the right metaphors and a little bit of backtracking and foundation-building, even complicated ideas like emulating classes and single inheritance can be understood and even implemented by young students. If I taught them lua reserved keywords, and a couple little math tricks here and there, they usually would all bunch up everything into a couple huge functions, and their game would (sort-of) work but be impossible to reason about, and very painful to extend. Introducing objects as a way to represent things that they want the game to do (draw things, shoot things, eat things, etc), it becomes clear to them that there is merit in structuring programs with objects beyond "shrugger says to do it like this!" OOP on its own doesn't make much sense. You can't teach someone to drive stick shift if they don't know what a car is. Maybe you could, but that's probably even worse.
- zerohp 10y ago
  When the ECE department at my university revised the undergrad Computer Engineering curriculum, they rejected the CS introductory courses partly for this reason. They also want to teach hardware first, but more importantly they teach "systematic decomposition" from the very beginning (before they teach programming) and leave OOP for future course work.
taneq 10y ago
> It's totally inappropriate - most of these students would fail fizzbuzz. Maybe this is related to the common occurrence of people who can provide stellar answers to interview questions about inheritance hierarchies and object composition... and yet can't pass a basic fizzbuzz style test?
- Sir_Substance 10y ago
  It may actually be directly caused by it. If you want people to come to your university, you need good post-degree employment figures. If every tech interviewer phone-screens by asking about multiple inheritance and red-black trees, it's really not surprising that universities might tip the curriculum towards that sort of thing at the expense of actual programming experience. After all, if you can't pass the phone screen you'll never get the opportunity to write code.
optforfon 10y ago
Have you actually talked to educators about this? I've asked a few why OO is the first thing you learn - and the reasoning was two fold: 1) People that start off by learn imperative programming end up writing really really shitty OO code. They're they type of people that end up copy and pasting stuff everywhere. It's really hard to get students to not take the "short cut" of copy paste to think in objects when you have homework deadlines and other things to worry about (and the teacher never actually spend time to teach you how to use programming toolchains...) 2) it's conceptually one of the biggest stumbling blocks for people. A lot of people have trouble wrapping their heads around OO. So sure you could teach it later, but it'll never sick or sink in.
- jacquesm 10y ago
  Nothing stops OO code from being imperative.
- 9182391231 10y ago
  People have trouble understanding OO because usually it is presented informally with insufferable dog/cat/mouse examples. Moreover, the fact that "subclassing==subtyping is unsound" is swept under the rug. A lot of people actually grasp the latter at an intuitive level, that's why they're never comfortable with objects. OO should be taught as abstractly as possible (I recommend Didier Remy's writings). After grasping the concepts, many people will conclude that they'll be better off with FP and modules.
  - AnimalMuppet 10y ago
    > subclassing==subtyping is unsound Could you explain what you mean by that, and why you think it's true?
userbinator 10y ago
OOP should be something you only get into after you have written some practical programs I'd modify that to "practical programs that are nontrivial enough to benefit from OOP", just like how I advocate not teaching about functions until they become useful. IMHO the CS curriculum should start with the low-level basics and work up from there in a natural progression: - Representation and interpretation of binary data. - Basic straight-line computation (more like calculation), concept of instruction execution - Flow control: decisions, loops - Functions/procedures/subroutines - Grouping data together: Arrays/structures/records/etc. - Basic OOP, grouping data and code together: Objects, composition, inheritance - Advanced OOP: virtual functions/polymorphism/etc. I have worked with some of that type of Java-student you mention, and it is astounding how many can create huge object-oriented monstrosities (including design patterns), the bulk of which are object creation and method calls, while not understanding arrays or even basics like why datatypes have a finite range. Their code has more object creation and method calls than branches, loops, or simple computational statements. Given that sort of inverted knowledge they have, that they fail fizzbuzz is not surprising at all. It also explains a lot of the inefficiency and bloat in most software. It's somewhat like teaching calculus to students who don't know arithmetic.
- mercer 10y ago
  Would it make sense to not jump to only OOP after 'grouping data together', but to provide FP approaches in parallel?
jdmichal 10y ago
This is the consequence of not teaching domains of problem-solving through actual problem-solving. You see the same thing in math. I had an excellent practitioner of this method for AP calculus. I learned limits by attempting to find the area under a curve using ever-shrinking rectangles, until we got to pushing them to zero width. And now, 15 years later, I still remember the concept. I don't necessarily remember how to do any particular problem involving limits, but I know what limits are and when they apply to a problem.

by lacker 10y ago

stevedonovan 10y ago

OOP made sense to people who already knew structured programming and understood functional decomposition (what we now call 'refactoring'). Perhaps education should start with that and then justify OOP? I remember reading about the original LOGO experiments; one thing kids do not spontaneously do is break up their monolithic actions into sensible functions.

lacker 10y ago
Yeah "breaking up a complex function into simpler functions" is a great example of something that isn't taught well today, yet is simpler and more critical than what we try to teach people in intro courses. I think of it in analogy to math. OOP is like topology - it's definitely useful in some cases, it's not too hard for an experienced mathematician to get the basics, and yet in a lot of situations it's irrelevant and it doesn't really belong in the first class you take. Being able to solve fizzbuzz is like doing arithmetic. If you can't solve fizzbuzz then you aren't going to be able to really get any advanced concepts. It's like you can't be a good mathematician if you can't figure out whether 351 is an odd number - you need to learn the basics first, even if "real math isn't about arithmetic". Sadly, you can tell if you do a lot of phone screens that many people who graduate with CS degrees still can't code fizzbuzz. Our CS education is busted right at the beginning. It needs to get the basics right, like, can you write loops, can you write functions. Today it is failing at that.
- mercer 10y ago
  Perhaps inheritance is easier to teach, which might be completely unrelated to how useful it is in practice? That would explain a lot. It reminds me a bit of how I was taught basic economics, where societies go from barter to currency. Apparently this is not true at all, but it's a story that is easy to teach.
TickleSteve 10y ago
Functional decomposition != refactoring. They are two completely different processes. https://en.wikipedia.org/wiki/Functional_decomposition https://en.wikipedia.org/wiki/Functional_decomposition https://en.wikipedia.org/wiki/Code_refactoring https://en.wikipedia.org/wiki/Code_refactoring
- emsy 10y ago
  Breaking up a large functions into smaller functions isn't even (strictly speaking) functional decomposition because not every sub-function might be dependent on the previous function. "Extract function" is a kind of refactoring, but not refactoring itself.
shrugger 10y ago
That is exactly true! I have experience teaching kids Lua, and with the right metaphors and a little bit of backtracking and foundation-building, even complicated ideas like emulating classes and single inheritance can be understood and even implemented by young students. If I taught them lua reserved keywords, and a couple little math tricks here and there, they usually would all bunch up everything into a couple huge functions, and their game would (sort-of) work but be impossible to reason about, and very painful to extend. Introducing objects as a way to represent things that they want the game to do (draw things, shoot things, eat things, etc), it becomes clear to them that there is merit in structuring programs with objects beyond "shrugger says to do it like this!" OOP on its own doesn't make much sense. You can't teach someone to drive stick shift if they don't know what a car is. Maybe you could, but that's probably even worse.
zerohp 10y ago
When the ECE department at my university revised the undergrad Computer Engineering curriculum, they rejected the CS introductory courses partly for this reason. They also want to teach hardware first, but more importantly they teach "systematic decomposition" from the very beginning (before they teach programming) and leave OOP for future course work.

taneq 10y ago

> It's totally inappropriate - most of these students would fail fizzbuzz. Maybe this is related to the common occurrence of people who can provide stellar answers to interview questions about inheritance hierarchies and object composition... and yet can't pass a basic fizzbuzz style test?

Sir_Substance 10y ago
It may actually be directly caused by it. If you want people to come to your university, you need good post-degree employment figures. If every tech interviewer phone-screens by asking about multiple inheritance and red-black trees, it's really not surprising that universities might tip the curriculum towards that sort of thing at the expense of actual programming experience. After all, if you can't pass the phone screen you'll never get the opportunity to write code.

optforfon 10y ago

Have you actually talked to educators about this? I've asked a few why OO is the first thing you learn - and the reasoning was two fold: 1) People that start off by learn imperative programming end up writing really really shitty OO code. They're they type of people that end up copy and pasting stuff everywhere. It's really hard to get students to not take the "short cut" of copy paste to think in objects when you have homework deadlines and other things to worry about (and the teacher never actually spend time to teach you how to use programming toolchains...) 2) it's conceptually one of the biggest stumbling blocks for people. A lot of people have trouble wrapping their heads around OO. So sure you could teach it later, but it'll never sick or sink in.

jacquesm 10y ago
Nothing stops OO code from being imperative.
9182391231 10y ago
People have trouble understanding OO because usually it is presented informally with insufferable dog/cat/mouse examples. Moreover, the fact that "subclassing==subtyping is unsound" is swept under the rug. A lot of people actually grasp the latter at an intuitive level, that's why they're never comfortable with objects. OO should be taught as abstractly as possible (I recommend Didier Remy's writings). After grasping the concepts, many people will conclude that they'll be better off with FP and modules.
- AnimalMuppet 10y ago
  > subclassing==subtyping is unsound Could you explain what you mean by that, and why you think it's true?

userbinator 10y ago

OOP should be something you only get into after you have written some practical programs I'd modify that to "practical programs that are nontrivial enough to benefit from OOP", just like how I advocate not teaching about functions until they become useful. IMHO the CS curriculum should start with the low-level basics and work up from there in a natural progression: - Representation and interpretation of binary data. - Basic straight-line computation (more like calculation), concept of instruction execution - Flow control: decisions, loops - Functions/procedures/subroutines - Grouping data together: Arrays/structures/records/etc. - Basic OOP, grouping data and code together: Objects, composition, inheritance - Advanced OOP: virtual functions/polymorphism/etc. I have worked with some of that type of Java-student you mention, and it is astounding how many can create huge object-oriented monstrosities (including design patterns), the bulk of which are object creation and method calls, while not understanding arrays or even basics like why datatypes have a finite range. Their code has more object creation and method calls than branches, loops, or simple computational statements. Given that sort of inverted knowledge they have, that they fail fizzbuzz is not surprising at all. It also explains a lot of the inefficiency and bloat in most software. It's somewhat like teaching calculus to students who don't know arithmetic.

mercer 10y ago
Would it make sense to not jump to only OOP after 'grouping data together', but to provide FP approaches in parallel?

jdmichal 10y ago

This is the consequence of not teaching domains of problem-solving through actual problem-solving. You see the same thing in math. I had an excellent practitioner of this method for AP calculus. I learned limits by attempting to find the area under a curve using ever-shrinking rectangles, until we got to pushing them to zero width. And now, 15 years later, I still remember the concept. I don't necessarily remember how to do any particular problem involving limits, but I know what limits are and when they apply to a problem.