Tuesday, February 01, 2005

Mistakes

I'm a TA for
Robert Harper's
course in constructive logic. He is
probably the best teacher I've ever had.
(For the cognoscenti, he is an author of the definition of
Standard ML ,
a founder of

logical frameworks
in their current form, and is a
pioneer of many other concepts in programming languages.
I had him for a
type systems course last semester. He spends hours
preparing each lecture, and has the entire scope of each
course prepared in his mind before he begins the
semester. The homeworks and final exam for type systems were all
inspired. I learned so much. Perhaps that's why I was so
shocked when he got mixed up today. He was lecturing on
normal derivations. He got some of the rules mixed up in
the beginning and was caught by the other TA shortly
thereafter. (I was frantically writing the next homework
assignment, so wasn't paying much attention at this point in
the narrative.) He recovered from that, but got mixed up by
some repeated questions by students further on in the
lecture. The questions all centered around the reason for
distinguishing normal proofs in the first place. He started
explaining, and stopped. Started a different way... and
stopped. It was really interesting to see his response.
He asked someone in the class to help him out. He could
easily have waved his hands and gone on. I'm certain no one
would have noticed. But instead, he apologized for
confusing people (after one question, he prefaced his answer
with "I'm the reason you're confused"). The class happened
to end at this point, and we adjourned. At the TA meeting
later that day he explained what he was trying to present.
He had actually solved the problem at a much deeper level,
but knew he couldn't use his solution. An easy one existed,
though, and he didn't come up with it. Noticeably
embarrassed, he told us that once
you lose your focus in lectures it can be hard to get on
track again.


This experience was thought provoking for a number of
reasons. First, it's nice to know that even people as
brilliant as RWH and as well prepared as I know he was
makes mistakes! That is probably the shallowest
observation however. The beauty of it was how he humbly
asked for help from the class. There was no sense of
egotism. He was very honest in the fact that he had
confused himself, and promised to present a clear account at
the next lecture. He immediately revised his notes on the
web, and told us (the TAs) how to present the problem
tomorrow. I was, again, thoroughly impressed with how he
handled the entire situation.


I saw the Kalichstein, Laredo, Robinson Trio play Mozart,
Danielpour and Brahms last night. Jaime Laredo played and
recorded with Harold Wright at Marlboro. It was cool to see
him in person. Kalichstein was my favorite by far. I
haven't heard him since I saw him at Carnegie Hall playing
Schumann. The Danielpour was my favorite of their
performances. The piece was called "A Child's Reliquary"
(1999), commissioned for their trio. It was really
fantastic. It was an interesting contrast from the
Gondoliers (community theater) this weekend ((sigh)).


I accidentally listened to Leon Fleisher play Mozart with
Szell and Cleveland. I forgot what a beautiful player he
is. I was so inspired to practice.


I reorganized my room so that I can do yoga. It's working
pretty well. Hopefully I'll be able to keep up a home
practice this time.


"... I feel myself a naturalist and a physician both; and
that I am equally interested in diseases and people;
perhaps too, that I am equally, if inadequately, a
theorist and dramatist, am equally drawn to the scientific
and the romantic, and continually see both in the human
condition, not least in that quintessential human
condition of sickness--animals get diseases, but only man
falls radically into sickness."
-- Oliver Sacks, "The Man Who Mistook His Wife For a Hat"

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