drick@hplvle.UUCP (drick) (02/14/85)
[generalized bug trap]
Recently, I interviewed someone who claimed to have a lot of
coursework in communication theory. The recent discussion of
Dirac's delta function (function used advisedly) reminded me
of a problem I gave this interviewee, to wit:
The Fourier Transform is defined as:
F{f(t)} = F(w) = Integral[-inf,inf]: f(t)e^(-jwt)dt.
[ j is the square root of -1, w is usually omega ]
a. Prove that F{ d(f(t))/dt } = jwF(w).
(What assumptions are necessary?)
b. If f(t) is the function sketched below [here I substitute the
definition because graphics work poorly on the net], find F(w).
(Hint: use the result of part a.)
f(t) = -1/T, -5T/2 < t < -T
2/T, -T < t < T
-1/T, T < t < 5T/2
0, else.
c. What happens to F(w) in the limit as T approaches zero? What does
this suggest about f(t)?
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If I express any opinions in this note, they are my own.
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David L. Rick
...!hplabs!hplvla!hplvle!drickgadfly@ihu1m.UUCP (Gadfly) (02/22/85)
-- > Recently, I interviewed someone who claimed to have a lot of > coursework in communication theory. The recent discussion of > Dirac's delta function (function used advisedly) reminded me > of a problem I gave this interviewee, to wit: > > The Fourier Transform is defined as... > > ...a. Prove that F{ d(f(t))/dt } = jwF(w). > (What assumptions are necessary?) > ... > > David L. Rick > ...!hplabs!hplvla!hplvle!drick Ah yes, HP's infamous interviewee interrogation. When will they wise up and figure out that there are much more productive, and certainly less insulting, ways to discover qualified applicants? Such non-standard and uncontrolled quizzing flirts with antidiscrimination laws, and I wouldn't be surprised if one of these days they got sued. -- *** *** JE MAINTIENDRAI ***** ***** ****** ****** 21 Feb 85 [3 Ventose An CXCIII] ken perlow ***** ***** (312)979-7188 ** ** ** ** ..ihnp4!iwsl8!ken *** ***
vdb@hou2g.UUCP (R.VANDERBEI) (02/22/85)
The problem suggested is quite easy and is a good test of an applicants analytical abilities. The only prerequisites are knowledge of the definitions of the integral and the derivative. The person who claimed that such a quiz is discriminatory reminds me of the old adage: ignorance is arrogant.
ndiamond@watdaisy.UUCP (Norman Diamond) (02/22/85)
> > The recent discussion of > > Dirac's delta function (function used advisedly) reminded me > > of a problem I gave this interviewee, to wit: > > The Fourier Transform is defined as... > > ...a. Prove that F{ d(f(t))/dt } = jwF(w). > > (What assumptions are necessary?) > > ... > > David L. Rick > > Ah yes, HP's infamous interviewee interrogation. When will they wise > up and figure out that there are much more productive, and certainly > less insulting, ways to discover qualified applicants? Such > non-standard and uncontrolled quizzing flirts with antidiscrimination > laws, and I wouldn't be surprised if one of these days they got sued. > > ken perlow It's far better than the random manner a lot of other companies interview applicants, with their uninformed personnel departments. In both cases, a lot of qualified applicants will be ignored, but the odds are not as bad in HP's case. -- Norman Diamond UUCP: {decvax|utzoo|ihnp4|allegra|clyde}!watmath!watdaisy!ndiamond CSNET: ndiamond%watdaisy@waterloo.csnet ARPA: ndiamond%watdaisy%waterloo.csnet@csnet-relay.arpa "Opinions are those of the keyboard, and do not reflect on me or higher-ups."
gwyn@brl-tgr.ARPA (Doug Gwyn <gwyn>) (02/23/85)
> Ah yes, HP's infamous interviewee interrogation. When will they wise > up and figure out that there are much more productive, and certainly > less insulting, ways to discover qualified applicants? Such > non-standard and uncontrolled quizzing flirts with antidiscrimination > laws, and I wouldn't be surprised if one of these days they got sued. It wouldn't surprise me if it really WERE against the law to discriminate on the basis of knowledge and intelligence. So long as the same quiz is given to all interviewees for the position, how could one consider it unfair? At my two previous places of employment, we had programmer qualification quizzes that did a very good job of finding out what a person's strong and weak points were before hiring him. In the few cases where we hired in spite of the person's poor showing on the tests, we later regretted it. Please note that designing a GOOD qualifying test is not easy and is best left to experts at test design.
dgary@ecsvax.UUCP (D Gary Grady) (02/25/85)
<>
We (meaning all of us) have a real problem caused by the education
racket: A degree represents time spent in a classroom and that's about
it. The only way to acquire credentials is to take courses. I have a
degree is physics but I have worked only in public relations and
computers (in which I have zero formal credentials). I would like to be
able to get an MS, say, in computer science, but that would require my
doing classroom work most places. Ditto in PR and journalism. Why?
That's just the way the system is set up.
So it's no wonder that HP and other firms have resorted to on-the-fly
testing of applicants either in interviews or in testing sessions.
Otherwise (going by degrees) they risk excluding excellent candidates
and including poor ones who happen to have degrees.
Still, I object to the casual use of multiple-choice tests in employment
and in nonacademic credentialing (CDP etc). Their reliability is very
questionable and their "cultural bias" is well known. I think a
multiple choice programming test is silly on the face of it. It reminds
me of Johnny Yuhn's line about his black belt. "It's much easier to get
a black belt in Korea," he says. "It's just a written exam."
--
D Gary Grady
Duke U Comp Center, Durham, NC 27706
(919) 684-3695
USENET: {seismo,decvax,ihnp4,akgua,etc.}!mcnc!ecsvax!dgary