Archive for the ‘Grading’ Category

Photo on 1-14-15 at 11.54 AM

my three top course requests
were offered to me a couple
hours ago. sure, i’d rather
be the lecturer for any *one*
of ’em than grade for all three.
but i look to learn a lot of math
and get paid doing it, so what
the heck.

when i took the course as a student,
brown-and-churchill was in about its
3rd edition (and didn’t cost two hundred
american dollars as it now appears to do;
the copy you see here belongs to the
math department of course). the beat-
-up old doorstop (_probability_) i’ve
never seen before. i didn’t even know
springer *made* such things. shame.
i’ll draw on some of the much-more-than-
-ample whitespace… but that won’t
excuse it. awake, awake, U.S.~ignobility.
solomon’s lecture-note packet promises
to be outstanding. i’ve worked with the
second-semester chapters (in a separate
in-house packet) and was way impressed.
also it doesn’t break anybody’s budget
that might want to actually, you know,
*own* the doggone thing.

getting back to work.


(if i now recall correctly).

(i think i’ve finally *now*
got my schedule for the
quarter… two linear analyses,
two analysis-twos, and a
discrete… into synch with
my life-itself schedule [so
that i’ll usually know things
like who i’m typing to, about
what class, and why. all i
need is some regular sleep
to start remembering things).

TAKE OFFENSE convention is a dumb
thing that happened; one should ignore
it when not typing for the internet.

if it’s the way i’m most comfortable doing it,
well it’s *my* handwriting and probably more
legible than that of most of my readers at that.

and if a student thinks that the language
“abuse of notation” means i think they’re
doing something very wrong? they’re not
wrong about *that*. if they think *i’m* being
“abusive” in using what you and i both know
to be a common turn of the phrase in math
departments? they’re flat-out wrong.

alas, the upshot of all this. i’ll be commenting
less, probably a lot less. so much the worse
for the students who might’ve found my
(well-informed, thoughtful) remarks useful.
so much the worse for my ideal of having
done anything but serve as a rubberstamp
for chump change. one should know better.

if we don’t let BS artists get away with murder
in these classes, there won’t *be* any class…
and they know it. “harsh” might’ve motivated
a small few actually to take something seriously
that would otherwise have done some other
thing (like scratch out a copy of somebody
else’s work, worse than the original, because
this whole thing is just a silly little ritual anyway;
there’s a lot of that [for example; i *don’t* say…
because i don’t know… anything about the
particular student with the “abusive” remark]).

nothing a grader… or a lecturer… can do
will change the nature of large-enrollment
“weeder” courses. and i’ll’ve been some-
what naive to think of ours as any other
kind of course just because the book
is actually written well (modulo the hints).

ah, well. getting back to work. one
more thing.

i’ll quit the job laughing before i try
to change my handwriting around to
suit the whims of some silly beginner.

gee this is embarrassing.
i found the work i owe you,
done, in a cubbyhole on my desk,
just now. and only then remembered
having done the whole thing
friday night (and feeling quite
proud of having done so; you
know what goeth before a fall).

and yet i *was* on campus yesterday.

you’ll have it first thing tomorrow.

lame excuse alert:
i did “an all-nighter” starting on
sunday evening so as to get another
stack done for another class and lost
all sense of time and space and what
the devil i was supposed to be trying
to do around here.

as for the grade-entry. yick, of course.
but not *nearly* as bad when the problems
are presented in their natural order as when
they’re *randomly* ordered.

this i consider an insult to me:
it’s *very* frustrating paging around looking
for scores and checking for completeness
because some student wouldn’t take the time
to organize their own work (as if their time
were somehow much more valuable than mine).

some instructors require very rigid standards
in formatting (name and date in upper right,
staple in upper left, etcetera etcetera).
it’s good for me as a grader when they do
but i never ran my own lectures that way
and sure wouldn’t ask anyone to.

properly-ordered copy is another story.
i’ll penalize Out Of Order starting with HW3.

but the real issue is always:
how “rigorous”… how “correct”, really…
should the *writing* be.
answer: much *more* than what i’m seeing.

there’s some amazing good work in these stacks.
and some embarrassingly careless stuff too.
i need to see *full sentences*
with all the articles (a, an the)
and having *subjects*
(that are clearly named: “it” is seen everywhere
but “it” is often unidentified by any language
on its page)
and with its *words spelled out*
(the sign of equality, =, for example,
must *not* be used as if it were
shorthand for “is”):
(one special case deserves mention here:
$\Rightarrow$ (the logical “implies” symbol)
appears essentially at random on many pages.
faculty do this, too. no use trying to penalize it.
still. yick.)

but much the hardest issues in reading
sketchy telegraph-style hide-the-weakness
student work comes out in the little words like
“for” and “and” and “so”. the logic gets
pretty twisted.

i end up spending a *lot* of time trying to resolve
things that the student darn well *ought* to have
tried to make clearer.

some of them know this and write badly *on purpose*.

so let me ask you to urge them to take

and to code carefully.
f \not= f(x)
and stuff like that.

i’ve gotta get back to marking.
sorry for the blown deadline.
i’ll try to see you when i drop off papers
later today.

skynet permitting

i’m planning on a campus trip monday
so look for me at bernie’s afterwards.
i might even stay for the monday medley.
anyhow, *i’ll* plan on banging around
a bit out on the smoker’s deck or what-

leaving only the “typing it up worse
for the net” to me… the \TeX-set
homework i’m about to loosely base my
plain-text solutions on is quite a lovely
thing to look upon… as my versions will
not be. now. make it so.

Let a/b, a’/b’, and a”/b” be consecutive fractions
in the Farey sequence of order n.

(i.e., in
F_n = {0/1, 1/n, …, 1/2, … , (n-1)/n, 1/1}
[for the record… it’s convenient to
have a “symbol” for this sequence;
F-subscript-n is standard but the
text doesn’t include it.]
We will show that these fractions
satisfy the “Mediant Property”:
a’/b’ = (a+a”)/(b+b”).

Consecutive “Farey fractions”
satisfy Theorem 6.1 and so
a’b – ab’ = 1 and
a”b’ – a’b” = 1.

Equating the left-hand sides,
a’b – ab’ = a”b’ – a’b”.

Regroup; factor;
“divide through by b'(b+b”)”:
a'(b+b”) = b'(a”+a)
a’/b’ = (a+a”)/(b+b”).
(We are done.)

let p be an odd prime &
let g & g’ be primitive
roots (mod p).

any Primitive Root, h, satisfies
(h^{{p-1}\over2})^2 = 1 (mod p);
since h^{{p-1}\over2}\not= 1 (mod p)
[this uses “h is primitive”],
we can conclude that
h^{{p-1}\over2} ~ -1 (mod p).

etcetera. forget it.
the handwritten stuff
is beautiful though.
\TeX is too hard.
it’s not so bad in the real editor,
of course.

oh, ps. (gg’)^[(p-1)/2]
is now seen to be congruent
to 1… and so is not a
primitive root (which, on
the day, was to’ve been shown).

so when i came back to work today
after being laid off all summer,
i just logged right in on the first try.
and into a better environment for working
in wordpress, too (than what we’ve got at home…
even when i use the 17″…)

it’s quite a large grading load:
advanced calc, vector analysis, and lots
of good old linear algebra. (i’ve also
committed to a writing project in intro
to calc… so it’s busybusybusy for me
for quite some time to come.)

now, where’s that doggone *textbook*?
… around here somewhere…

(first post since the name change.)

things’re going fine all around…
other than some computer-interface
hoo-hah snafu-ing the grade entry…
and it’s about time for the first test.

which the lecturers grade for themselves
according to the usual department practice.
so there’ll be maybe a little better chance
of me actually *posting* something around here.

meanwhile, let me go ahead and report for today
that for quite a while now i’ve actually been
*reading mathbooks* pretty avidly again.

recently it’s been one of my favorite
work-avoidance tricks.

reminding me of nothing so much as myself
in grad school when i’d spend hours in the
math/physics/computo-stuff library (in swain
hall west) avoiding the actual sit-down-and-*try*-
-something work that horrifies almost all beginners.

browsing around in the stacks at IU…
i didn’t neglect the *main* library
or that of the education school…
certainly wasn’t a *waste of time*.
i was one of the best-read amongst
a bunch of *very* smart people and
learned a lot of “math culture” stuff
most grad students never find time for.

because they’re, you know, actually *working*.

certainly it’s a relief to look over well-
-reasoned (& sometimes even well-written!)
work after… or during… a marathon session
of correcting basic-mistakes-stubbornly-
-clung-to created by students who should
have long since known much better. (it all
starts with the “=” sign… but [for now]
i’ve ranted enough on that matter in earlier

and now that i’m mostly working with my *own*
books… almost entirely gotten on the cheap,
i assure you… “free” and “dover” are the
biggest categories here… i feel (more) free
to *write in ’em* (as i should’ve been doing
much more of all along [in *pencil* of course!]).

making my avoidance-technique that much more like
the actual work, you see.

heck, even *crossword puzzles* (usually
a big enough part of any go-to-campus-&-back
day since i almost invariably work ’em on
the bus) have a certain reading-and-writing
… and even *problem-solving*… feel to ’em.

so i’m spending a *lot* of time in some
mathy-or-anyhow-*kind*-of-mathy state.
immersed in the world of symbols-and-syntax
(or of concepts-and-code if you prefer…
i’ve got a million of ’em…).

and i *like* it like that. the trick is
to avoid, not facing-down-unfamiliar-symbols
or even grading, but, you know, those messy
“real world” encounters with other beings.

some math users… famously the great pascal…
have even reported an anesthetic effect
(he used analytic geometry against toothache).

the *dreams* you get from a math OD, though?
usually not so good in my opinion. usually
it’s too much like real life: not “one
damn thing after another” but the *same*
damn thing, over and over.

anyhow. past bedtime now. wish me luck.

gainfully employed

grading linear algebra again.
so far this quarter, i’ve (1) returned
the text from last quarter (late) and
i’ve (2) gone back and got a different
copy of the same text a week later.
and that’s it… a week and two days
into the semester.

but starting today there’ll be bigfat
envelopes full of homework piling up
in my mailbox. so very likely i’ll be
posting less over in the cooking show
(where i’ve had a pretty good run going
for about a week).