software engineering;  was: Is this official blog article intended as a joke?

Actually, the 'blog makes a useful point:

Most computer science students get to learn high-level programming languages and application development but they don’t really understand computers.

JMO/YMMV:

Now, while interfacing to the real world is fun, RasPi doesn't really address the high-level application problem.  It's still a GNU/Linux box, running a mainframe operating system with dozens of processes.  It's darn cheap for a mainframe, but it's still a mainframe.

If you really want to learn what computers do IMO you really need to learn assembly language and run it on a real mini- or micro-computer with no operating system present to protect you from stomping all over your code and data so that your program goes off to la-la land.  That's when you really see that all that's in computer memory is bit-strings, and the computer will interpret them as instructions or data depending on where you told it to execute -- whether you meant to or not.  Once you've mastered the machine-language level, then you can understand why your C program is misbehaving in that extraordinary fashion.  IMO this mastery is necessary for someone to be called a computer scientist, just as you expect an EE to know how to use Kirchhoff's Laws and a mathematician to be able to do Epsilon-Delta proofs.

> IMO this mastery is necessary for someone to be called a computer scientist,

Of course, computer science is a big field, with many specialties, and many layers

of abstraction, and it's entirely possible for hardware specialists to know very little

about software, and vice versa.  And theoretical computer scientists often know very

little about either software or hardware, focusing their attention on topics like

algorithmic efficiencies that don't provide any benefit on realisitic sized data sets.

Dijkstra famously said "computer science is no more about computers than

astronomy is about telescopes."

Of course, it's still important to know how to read an abend dump when you have to.

I accept that abstraction is necessary, but I'd argue that it's a necessary evil.

Yes, no doubt that large companies, nations, etc. are run with huge inefficiencies.

Sometimes that is intentional.

Similarly, there are a lot of examples where inefficiency is inherent. 

For example, airliner load factors.  It's tempting to see an airliner flying

with empty seats, and say that's inefficient because the seats are

going to waste and any revenue that could be obtained by filling them

would go directly to the bottom line profit. 

But an airline intentionally flys more seats on any particular route than

it expects to fill, in order to accommodate last-minute bookings from

high-paying business travelers.  It's just as important to avoid the waste

of turning away last-minute bookings because your plane is full than it is

to avoid the waste of flying empty seats.

The idea of abstraction is that low-level details are often not of critical

importance at higher levels of design.  For example in coding, an

assembly language programmer might care a lot about which register

holds which variable, in order to maybe keep two variables in adjacent

registers so they can be moved at the same time in a single double-word

move instruction.  But that's of no concern to the project's chief architect.

Every low-level detail needs to be worried about by someone, but

no single person needs to worry about every low-level detail.

Great post, Nelson.  I really like the Orson Scott Card essay -- hilarious and insightful.

Dudley Nelson wrote:

 

Ultimately, it's quite possible to write bad code in any language. The more powerful the language, the easier it is to paint yourself into a corner, and find yourself with a sticky problem that you have to fudge your way out of...

Reminds me of some classic C versus C++ jokes (from memory):

1.  C gives you enough rope to hang yourself.  C++ gives you enough rope to tie up everybody in your neighborhood, rig a small ship, and still have enough left over to hang yourself from the yard-arm.

2.  With C, it's easy to shoot yourself in the foot.  With C++ it's harder, but when you do you blow your whole leg off.

Dudley Nelson also wrote:

 

Now, that all said, it's fair to say that all software ships with bugs; it is part of the nature of software, and it happens for all the reasons everyone said.

All software that performs a non-trivial function has bugs.  There are just way too many moving parts, and when you try to fix the code the bugs scurry away to other parts of the program, just like in the song:

99 little bugs in the code,
99 bugs in the code...
Take one out, compile again,
100 little bugs in the code.
[Repeat until bug count goes to zero.]

As long as we're sharing humorous bits about software engineering, here's one of my favorites: Software Engineering: Now with Cats.

Dudley Nelson wrote

 

However, what got me out of lurking on this post and actually posting on this discussion was the last post by Selsinork, which reminded me of an excellent article once written by Orson Scott Card. This is a jaded example, but it definitely points at some of the key problems in software development - how it is handled by non-software types, and especially by management. The world has changed in many ways since this article was written, but in many ways, it remains the same. A large number of problems are caused by external people not understanding either how software works, or how the people who work on software work.

A great example of no matter how much things change they really just stay the same. I don't think that has lost any relevance in all these years.

coder27 wrote:

 

Every low-level detail needs to be worried about by someone, but

no single person needs to worry about every low-level detail.

I couldn't agree more.. Unfortunately it's also exactly the problem.  Someone five levels up the abstraction tree makes an innocuous decision because he doesn't think he needs to care about the person trying to keep those two values in the same register, but by the time the decision makes it all the way down, that assembly language programmer can no longer do what's required without forcing a re-write at every other level. Resulting bodged solution unsurprisingly has issues because a very frequently executed action goes from a single cycle to something that takes very many orders of magnitude longer.

I know of at least one example where this sort of thing forced changes in hardware to compensate for software design that was unchangeable due to this way of thinking.

John Beetem wrote:

 

As long as we're sharing humorous bits about software engineering, here's one of my favorites: Software Engineering: Now with Cats.

I like it

Someone five levels up the abstraction tree makes an innocuous decision because he doesn't think he needs to care ...

Yes, sometimes abstractions leak, but hopefully it's the exception rather than the rule.

As you probably know, there is a software engineering notion of "information hiding"

that is often misunderstood.  The goal is to separate interface from implementation,

with the implementation details hidden from users of the abstraction so that they can't

unwittingly rely on them, which would endanger the system if the details are changed.

Some people think information hiding is bad in that it prevents them from maximizing

efficiency by taking advantage of implementation details that they don't expect will

actually change, such as multiplying an integer by 2 by shifting it left one bit, on the

assumption that it's represented in base 2 and always will be.

Dudley Nelson wrote:

 

excellent article once written by Orson Scott Card. This is a jaded example, but it definitely points at some of the key problems in software development - how it is handled by non-software types, and especially by management. The world has changed in many ways since this article was written, but in many ways, it remains the same. A large number of problems are caused by external people not understanding either how software works, or how the people who work on software work.

Although poor management is common in all fields, the core problem in software isn't lack of understanding of software by non-software-types, but lack of understanding of software by everybody involved in the process, Alpha Programmers included.  In fact, the finger of blame should mostly point at the "geniuses" of the field because they should be informed enough to understand the root cause of the problem, and able to communicate it to others, including management and beancounters.  They aren't, and they don't.

After all, management deals with huge projects in many other fields of engineering and still succeeds in delivering bridges that don't fall down continually, complex modern cars that are much more reliable than their drivers, and space rovers that continue to explore Mars some 10 years after the end of a nominal 90-sol mission.  It is not beyond the capabilities of engineers and management to make extremely complex systems that work to spec.

Unfortunately, the vast bulk of software development is not an engineering discipline at all, but a rather ad hoc craft with very little in the way of engineering methodology, and frequently no measurement or analysis done at all.  Although Computer Science is a formal discipline, it underpins the creation of software only in principle, rarely in practice to any great extent.  Well-chosen scalable algorithms or the use of formal language grammars is often as close as CompSci gets to helping a software project achieve its goals.  The situation is very bad indeed.  The Software Crisis that was so often described in the 80's is still present and shows no signs of abating.  It's an extreme embarassment to those of us who would like to consider themselves engineers through long experience in the discipline, but in all honesty cannot.

Orson Scott Card's little article is certainly funny.  Unfortunately it also perpetuates the myth that  Alpha Programmers are on top of things, and that if only they were left alone, coders and their coffee and pizzas will solve everything.  If only it were so.

Morgaine.

Morgaine Dinova wrote:

 

Although poor management is common in all fields, the core problem in software isn't lack of understanding of software by non-software-types, but lack of understanding of software by everybody involved in the process, Alpha Programmers included.  In fact, the finger of blame should mostly point at the "geniuses" of the field because they should be informed enough to understand the root cause of the problem, and able to communicate it to others, including management and beancounters.  They aren't, and they don't.

My opinion:  I think a lot of great programmers got that way precisely because they've always been bad at communicating with humans.  They were ostracized as children, and bonded early to computers as an alternative.  To get stuff through management, it's not just communcication -- you have to sell yourself and your ideas.  Well, not everybody is a good salesman.  Those who are go into sales and make a whole lot more money than techies.  JMO/YMMV

coder27 wrote:

 

As you probably know, there is a software engineering notion of "information hiding"

that is often misunderstood.  The goal is to separate interface from implementation,

with the implementation details hidden from users of the abstraction so that they can't

unwittingly rely on them, which would endanger the system if the details are changed.

I think the key is designing excellent interfaces between layers and writing excellent documentation to define those interfaces so that people can develop separate pieces and have them work together properly when integrated.  This goes along with information hiding, since if the interfaces are designed and documented well enough there is rarely a need to peek beyond the interface.

coder27 wrote:

 

As you probably know, there is a software engineering notion of "information hiding"

that is often misunderstood.  The goal is to separate interface from implementation,

with the implementation details hidden from users of the abstraction so that they can't

unwittingly rely on them, which would endanger the system if the details are changed.

I think the key is designing excellent interfaces between layers and writing excellent documentation to define those interfaces so that people can develop separate pieces and have them work together properly when integrated.  This goes along with information hiding, since if the interfaces are designed and documented well enough there is rarely a need to peek beyond the interface.