Date: Thu, 11 Jan 2007 00:07:27 -0800
Reply-To: David L Cassell <davidlcassell@MSN.COM>
Sender: "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From: David L Cassell <davidlcassell@MSN.COM>
Subject: Re: sas interview questions, how to answer?
Content-Type: text/plain; format=flowed
> > I saw some interview question of sas, but I don't know the exact
> > answer, who can give me some hint, any help is greatly appreciated!
> > 1. have you ever linked sas code? if so, describe the link and any
> > required statements used to either process the code or step itself?
> > 2. What is the Program Data Vector(PDV)? what are its functions?
> > 3. Does sas 'translate' (compile) or does it 'Interpret'? explain.
> > 4.At compile time when a sas data set is read, what items are created?
> > 5. Name statements that are execution only.
> > 6. In the flow of Data step processing, what is the first action in
> > typical data step?
> > 7. what's the difference between var A1-A4 and var A1--A4?
> > 8.why is sas conisdered self-documenting?
> > 9.Briefly describe 5 ways to do a 'table look up' in sas.
> > 10. what are some good sas programming practices for processing very
> > large data sets?
> > 11.what are some problems you might encounter in processing missing
> > values? In data steps?Arithmetic ? Comparsion? Functions? Classfying
> > data?
> > 12. what is the difference between function PROCs that calculate the
> > same simple descriptive statistics?
> > 13. if you were given several sas data sets you were unfamiliar with,
> > how would you find out the variable names and formats of each dataset?
> > 14.
>Now hold on, folks, some of these are interesting questions. So don't
>be so dismissive.
But some of them are NOT. And some of them are really unclear.
> >From the user's point of view, SAS looks like an interpreter.
>I have used it for many years, so it does look like that.
>But in reality , it must be a just-in-time compile, because with the
>resources SAS has had for three decades, an interpreter makes
>absolutely no sense, especially for very large datasets.
It's a bit more than that, just as languages like Perl have addressed
the issue for speed purposes.
>Oh, and it looks like question # 4 actually gives the answer to
>question # 3.
>And people can use SAS for years and never have to link SAS
>No , SAS is not self-documenting. Is that really true of any language.
Not in my opinion. Not even COBOL or Ada.
But it certainly can be written more clearly than some coders do,
so you can make the code more readable and more informative.
>If you want to see more of my comments on SAS and other statistical
>software , you can check out stuff at datahelper.blogspot.com or
>Here's a question :
>What do you think the ratio of full-time SAS programmers to full-time
>SPSS programmers is?
>Or full time S-Plus/R programmers?
David L. Cassell
3115 NW Norwood Pl.
Corvallis OR 97330
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