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NNTP-Posting-Date: Fri, 23 Dec 2011 12:25:23 -0600
Date: Fri, 23 Dec 2011 10:25:12 -0800
From: Patricia Shanahan <pats@acm.org>
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Subject: Re: comparing two test files
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On 12/23/2011 9:18 AM, Gene Wirchenko wrote:
> On Fri, 23 Dec 2011 06:37:25 -0800, Patricia Shanahan<pats@acm.org>
> wrote:
>
> [snip]
>
>> I've written a web page on the subject of how to debug,
>> http://www.patriciashanahan.com/debug
>
>       Nice page.

Thanks.

>
>       How did you come up with that example?  It is very good.  The
> problem with cooking up examples like that is that one already knows
> what the problem is so any "detective work" is suspect.

I took a common student problem that needs a little attention to detail,
and wrote a Java implementation as fast as I could type, making minimal
changes to fix compile-time errors. I then went straight to test and
debug, writing up the debug steps as I went along, without doing any
desk checking.

Normally, my programming keystroke rate is a lot slower than my raw
typing rate. Suppressing self-checking and thinking about details in
favor of typing speed made a good collection of mistakes statistically
likely, but without giving me any knowledge of what the mistakes were.

I hoped the result would be a more realistic example and debug process
than if I had consciously inserted errors in an otherwise carefully
written program, and then pretended to find them.

Patricia