[Linux-aus] Extent of sco's complaint - birthday paradox

Jon maddog Hall maddog at li.org
Thu Jun 5 22:50:02 UTC 2003

leon at cyberknights.com.au said:
> There's another factor, too, called "The Birthday Paradox", whereby if
>  you have 23 people in a room, the odds are even that two of them
> share  a birthday. Applied to code, it means that some code is bound
> to look  the same once you get enough of it.

Ahem, I think you mean they share a day that they celebrate the anniversary
of their birthday.  Or the 23 people in the room are all of the same age.
To me, sharing a birthDAY means that they were born on the same day and year.
This is the stuff that lawyers love, the nit-picking. :-)

I could point out that (to me) code is much more like a fingerprint.  There
would seem to be only a certain number of combinations of swirls and loops
to make up a fingerprint, yet they can seem to determine who killed who from
them.  Imagine 60,000,000,000 fingerprints (assuming ten on each person)
and no two the same.  Snowflakes have also fascinated me.

I used to teach at the university level.  I would be checking over homework
handed in, and from time to time I would be checking a program and it would
have a "familiar look".  I would go back over some of the previously checked
papers, and.....there it was.  The variable names had been changed, and the
comments had either been removed or re-worked, but the "fingerprint" was
the same.  Holding up the two papers, and moving them back and forth showed a
"pattern".  Confronting the two students allowed me to find out who copied
who, but usually that was apparent anyway from their other work and study
habits.  This happened several times over my (relatively) short teaching career.

What we have to make sure of is that our "work and study habits" are squeaky
clean, so at the most the judge gives us a firm warming, and a "do better"
next time, assuming that he finds against us.

Jon "maddog" Hall
Executive Director           Linux(R) International
email: maddog at li.org         80 Amherst St. 
Voice: +1.603.672.4557       Amherst, N.H. 03031-3032 U.S.A.
WWW: http://www.li.org

Board Member: Uniforum Association, USENIX Association

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