> On Fri, 21 Sep 2007 16:31:04 +0200, Frans Bouma <[EMAIL PROTECTED]> wrote:
> >> On Fri, 21 Sep 2007 15:28:58 +0200, Frans Bouma <[EMAIL PROTECTED]>
> wrote:
> > Often no experience and likely not really that much education
really.
> >Say you have a guy who's 18. Does that person have a lot of education in
class
> >design, knowledge about what makes software maintainable etc. ? no. But
that
> >person can likely be able to write for you a killer quaternion based 3D
object
> >rotator. The right person for the job? He'll likely pass all your low-
level
>
> If he can learn to write "quaternion based 3D object rotator"...then he
> can probably learn how to do lots of stuff useful to me....
But he lacks serious knowledge of software engineering, computer
science. Being able to write code doesn't mean you know much about the
fundamental elements of computer science. Like a thing called a parser. Not a
lot of people know how a parser, lexical analyzer, grammars etc. work. What
LR(n) means, what the difference with LL(n) is and why it's a fundamental part
of computer science.
You don't need to know how it works to write a loop and a sorter.
Though the knowledge is key for a succesful software engineer. Let me refer to
Yegge for a brilliant piece why this is so:
http://steve-yegge.blogspot.com/2007/06/rich-programmer-food.html
Look, if you're looking for a guy who can hammer in code, you're
probably not looking for a person who knows fundamental stuff. But then this
person won't evolve further towards a software engineer he could be, only the
lucky ones will.
> > And even then: would you want to hire a C# developer who doesn't
use
> >framework classes for this? Or one who DOES use framework classes for this?
>
> don't care...I'm interested in how it's done.
You don't care? So you don't mind hiring a NIH (Not Invented
Here)-syndrom person?
> >> would it matter if it were a string or a set of delegates in a generic
> >> collection used for event handlers?...does that somehow make it more
> >> relevant?
> >
> > If someone is faced with these problems, they'll likely look up the
> >algorithm and implement that. You say it's a junior position. So the person
> >hired has little knowledge about all the algorithms out there, only a few
of
> >them are known by the person. So it's likely the person will run into
problems
> >which ask for an algo which isn't known.
>
> you seem to have the notion that all algorithms come from web sites....do
> you google every time you wanted to write a loop?....surely not.
algo != loop.
I also don't think algorithms just come from websites. I do know that
if you don't look for the algorithm, you'll likely re-invent it... poorly.
Unless it's a deadbeat loop of course.
> >> > Remember: interviewing for a job is often totally difficult
compared
> >> >to the real job.
> >>
> >> difficult? or different?
> >
> > different, my bad.
>
> yes....so?
so conclusions drawn from the PERFORMANCE of the person on the
interview are actually pretty flaky, IF the tests aren't that great, because
the pressure to do it right the first time and not to make a single mistake is
extremely high for the interviewee.
> >> > For example, most algorithms to use on a daily basis are already
> >> >discovered and documented in full on the internet and in books. Like
'sort
> >> >this DAG in the right order so all jobs represented by nodes are
enlisted
> >> in the right order for execution'. Sounds tough? No, it doesn't.
> >> ?
> >> I'm not asking them to invent an algorithm....just apply it.
> >
> > Topology sort of a DAG is simple graph math, every CS student gets
it.
> >So if someone can't do a depth first search through a graph, s/he has no
> >knowledge of graphs. It's not inventing an algo, it's a well known algo.
> That is, if you have had that education.
>
> I would not expect a junior or senior programmer to understand what you
> are talking about....I have a masters in maths......and I don't understand
> what you're talking about......it's the demonstration of knowledge....I
> want a demonstration of ability.
You have a degree in math and you don't know what a Directed Acyclic
Graph is? Topology sort is a simple algo based on depth based first graph
traversal, a typical math-applied-to-data structures Computer science example.
It's not really important, what I wanted to illustrate is that IF a
person knows a given algorithm, the person can answer the questions in the
field of the algo, but that doesn't say anything, only that the person
understands the algo.
I.o.w.: it doesn't test wisdom, just knowledge.
> > I mentioned it to illustrate that the algo YOU pick to test, might
be
> >well known or easy, but might be for others hard to do and vice versa.
> ?
>
> all algorithms are not created equally...
> I would expect all programmers to understand simple iteration...i.e. a
> loop.
duh. I expect them also to understand what control flow means, but
that doesn't mean anything w.r.t. algorithms.
> I would expect less than 10% to know anything about acyclic graphs....or
> at least in those terms.
You do? Graphs are a fundamental part of computer science. I bet
almost all programs have one or more graph-like datastructure internally, e.g.
a tree. So if a person had a good CS education, s/he would know about them and
a test based on them is easy for these people.
A person who did something else, has a hard time. If that person then
has to do the same test, s/he'll likely fail. That's illustrating the lameness
of these tests.
> > If you tell the junior to navigate through the graph and find all
> the
> >paths, it's the same as string reversal: the algorithm sounds OK, it tests
> >basic simple first grade programming 101 skills no-one bothers about, and
it
> >tells you nothing about the true knowledge of the person.
>
> what if they fail!
then nothing, they might got too nervous to write something solid, or
didn't have enough time or got lost because they don't have any docs at hand.
> > Did I pick the right person? Undefined: based on that algo test,
you
> >can't tell anything about the true skill of the person.
>
> no?
It's your interview, but I'd say: no.
> > EVERY programmer can write a simple loop. That's why these tests
are
> >so stupid!
>
> what if they fail!
the same thing as what if they succeed?
> the deduction that the information gleaned from a test that everyone (by
> premise) succeeds at is none, is trivial.
>
> YOU failed the test.....you didn't do it 'in place'.
hehehe, so you have made a conclusion, based on that? Yeah, I'm a
lousy programmer who can barely code his way out of a wet paper bag ;)
Of course I failed. You would too. Because it's impossible due to
technical limitations.
> > What's the point of testing procedural stuff in an OO environment?
Do
> >you want them to code procedural script-like OO code? Or do you want them
to
> >write OO code? Do you want them to write deep class hierarchies no-one will
> >understand? Or do you want them to do the right thing?
>
> OO is a generisation of procedural programming (at least in the context of
> imperative languages)....if they can't write procedural code....they can't
> write OO code.....I don't view (good) OOP as a basic skill.....I do view
> procedural programming as one.
fundamentally wrong, IMHO. A procedural oriented developer might be
able to write classes, and it looks 'ok', but the code inside the classes is
procedural, not OO. Code will likely ask data from objects to do stuff in a
method instead of telling an object to do things. Fundamentally different and
a procedural oriented person won't grasp that.
> > You can't determine that from isolated tests which test basic stuff
> >learned on page 1 of every language book.
>
> YOU failed the test.
> I assume you failed it, not because you can't do it, but because you
> didn't clarify the question....I would then make a note 'does not clarify
> requirements?'.
As a matter of fact I looked for the String.Reverse method, then I
remembered there was an array reverse method, so I went that route and mailed
it. Later on I realized the question itself was bogus because strings are
immutable.
One could argue that missing a requirement is bad. The in-place
requirement could have consequences for very large strings in-memory: not
doing it in-place isnt possible or very slow. (let's assume the strings are
mutable).
So yes, I've failed your test, in that light. Though my code was just
to illustrate that it's trivial which was your question.
> > So I failed your test and you would not hire me. See how silly this
> >is? :)
>
> I didn't because I researched the questions on the internet before asking
> any real candidates!....
>
> and if you had done the question you would have done nicely in the
> interview by pointing out it was impossible.
though that would illustrate nothing, just that I know strings are
immutable. The thing is: do you want a person who knows things about computer
science or do you want to hire a person who can hammer code? because those
aren't the same things. As it's a junior job, you likely want the latter, but,
it's very very hard without proper uni education to get from junior to the
spot where you do know about fundamental computer science elements WITHOUT
selfstudy. That'll cost a lot of selfdicipline, which his often ignored,
because why would you want to learn about those dry crap if you know how to
write a loop? ;) :)
> But thankyou.....reversing strings in place is not a sensble c#, question
> thats what the OP was about.
>
> Any thoughts about any other questions? :-)
Ask a complex algorithm, in line with the job, and not to let them
write it in code, but to let them explain how they will handle this.
But I think it's best to let them do an assignment in line with the
job.
FB
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