ch3cooh: (Winter)
I taught a class tonight that didn't work. It was somewhat fun, and somewhat well developed in presenting applications of game theory. But overall: :P I'm writing this post to note down thoughts before I forget, and I'm making it public because I generally think that various try-fail-learn processes should be more open/public. Also, I've been feeling awkward lately that I present myself so unilaterally as an 'experienced teacher' now, and not a student/new and learning teacher or in any other mind-set... more on that in the future perhaps.

I've decided to try for 2 focus goals of self-improvement in teaching each season. This season, my goals are (1) Time management via consciously prioritizing academic and non-academic goals, and (2) creating situations where my students feel ownership for what they're making.

Game Theory part III of IV

This activity was part of a 2 hour session for 45 students in 6th-8th grade.
1) The students cut out paper candy bars and then ranked each type (30 types) of candy bar 0-3 so that the sum of all of the types was 50.
2) In groups of four, I asked them to design an agreed 'fair' method for distributing the candy
3) They implemented the method, and the person to get the most total value of candy (using their own value sheet to scale) in each group, wins a real prize.

Time management went OK. I cut the activity a bit short (~1:15 total out of the 2 horus for the session) and extended some other parts of the class that were working better.

Review: Freedom to Experiment is one of the four foundational freedoms that I strive for when I teach (the 4 are: freedom to fail, experiment, of effort, and to try on different identity roles). But in order for an activity to feel like a valid experiment, there needs to be meaningful choices that the students understand when they are making those choices, and there needs to be feedback, ideally interesting, immediate feedback in response to their choices, and then a chance to go back and make those choices again, more informed. Here's where I think I went wrong:

1) Part 1 mechanics: there were too many types of candy and the max rank wasn't high enough. It should have been something closer to 6 types of candy, 15 points total, rank each from 0-10 I think.
2) Part 2 mechanics: I should have gone over more examples before setting students out to make their own. They had a lot of choice here, and I wanted them to have 'ownership' of their methods, but only a few groups really seemed to construct - most just fished around for something reasonable-seeming and then used that.
3) Part 3 mechanics: OK, but I should have had a sheet for describing more data about the results of using the algorithm -- showing which kinds of preferences or strategies would have the advantage and how and why.

Next time:
I think I should have had a first part of class dedicated to working with 3 or 4 very different division algorithms, letting students get a feel for which are best in different circumstances. Then part 2 could become combining these methods to make something more fair for everyone. Part 3 needed more organization, some follow-up questions with exact answers in addition to the . And I should have left time to play a 2nd time, without letting people change their ranks in-between, to illustrate the impact of making preferences public.

I spent 10-15 minutes in a few random blocks telling stories about how game theory has come up in scenarios I've seen:

Real estate needing to buy all of some set of houses in order to make any of those houses valuable, a sport conference leader needing to choose a mechanism for coaches drafting their teams, the Splash class lottery algorithm that I worked on as a college student, etc.

These stories hushed the room, and I think I could do more with them. I could ask students how they would 'game' each system, and then how to patch those gaps to make that kind of 'cheat' impossible.

Next time:
1) Real-life game theory examples
2) Trying out 3 or 4 simplified algorithms in groups of 4, with a smaller candy-set
3) Give groups time to build one algorithm from the existing ones
4) Have students implement it
5) Discuss what students chose to do and who it advantaged
6) Play again
7) Discuss the result of more-public value information

Big picture -- If I can make this class into a really excellent one, I think it would make a great introduction to the game theory sequence I've been building. I'm working on 8-12 class sequences right now, of sessions that can stand alone if they need to, but that tie together under a theme as well.

A) Designing Something Fair -- Real Life Game Theory, Types of Fairness
B) Designing Something Fair -- Pet (instead of candy) Intro
C) Designing Something Fair -- Design your own fair division algorithm
D) Designing Something Fair -- Fair Voting Lab

E) Comparing Strategies -- Monty Hall Intro
F) Comparing Strategies -- Prisoner's Dilemma (Iterative Play AI Design)
G) Comparing Strategies -- RPS and Rock Scissors (Mixed strategies)
H) Comparing Strategies -- Real life Game Theory, Nash Equilibria

I) Perfect Play -- Say 16
J) Perfect Play -- 2-pile Nim (poison points)
K) Perfect Play -- Dots and Boxes
L) Perfect Play -- Dots and Boxes AI + Tournament

Higher level Topics:
* Advanced Combinatorial Game Theory
- perfectly logical pirates
- proofs about combinatorial games
- gomoku and variants
ch3cooh: (Ball Pit)
Challenge: write up your initial instinct, then try to prove it and let me know what happens. :D
I really like this puzzle.  And I'm sure that there's a simpler proof than the one I'm using right now.


Solution )
ch3cooh: (Fringes of Chaos)
For context, I'm making an activity for high school students in an afterschool math program. The activity is aimed at estimating, understating, and working with really big numbers, and this part of the program (4 sessions) is focused on bijections and infinties, with a theme of how mathematicians think about topics that are too large or abstract to handle with intuition, and for how mathematicians make choices that shape what the mathematics we study looks like.
More Details )

The list so far:

* The approximate number of primes between 0 and 2^57,885,161 − 1 (???)
* If two 'opponents' at Go are actually collaborating to make the game as long as possible, approximately how many turns might the game last (on a 19x19 board)? (???)
* The approximate number of different chess games for which the board never returns to a previously experienced state. (???)
* The approximate number of atoms in everything living on the earth (???)

* The approximate circumference of the earth in miles (~10^4)
* The approximate number of sheets of paper in a stack as tall as the height of the Transamerica Pyramid in SF (~10^6)
* The approximate number of seconds in a human life (~10^9)
* The approximate number of people in the world right now (~10^10)
* The approximate number of neurons in a human brain (~10^11)
* The approximate number of seconds between now and when a dinosaur last lived (~10^15)
* The approximate number of ants in the world right now (~10^16)
* The approximate number of calculations that can be done by the world's current fastest computer (The Tianhe-2 supercomputer) in 1 minute (~10^18)
* The approximate number of stars in the universe (~10^30)
* The approximate number of atoms in the earth and everything on it (~10^50)
* The approximate number of different ways a deck of 52 cards might be shuffled (~10^68)
* The approximate predicted number of atoms in the universe (~10^80)
* The approximate number of rabbits that would exist in the universe after a year if, starting with 2 rabbits, ever day, every pair of rabbits alive mate and produce 6 offspring, and no rabbits ever die. (~10^219)
* The approximate value of the largest known prime number (~10^17425169)

See more at my ask MetaFilter page.
ch3cooh: (Fringes of Chaos)
These pictures are from the Elementary math circle program at SFSU.  It's a class I teach every Thursday with a coteacher, Josh R. :)  I have never taught with a coteacher this extensively before -- it's awesome!  One of the best parts is that he and I have very different mathematical backgrounds, so whereas the Graph Theory class I'm prepping for next week is foreign content for him, the past 3 weeks that we've spent studying sequences, building up the the Collatz conjecture is new content for me.

The ribbons the students (and instructors) are playing in are sequcens that start with any number of the students' choosing and then progress using the following rules:  If the latest number is even, divide it by 2 to find the next number.  If the latest number is odd, multiply it by three and then add one to find the next number.  The magic is that, so far, every initial choice of a number eventually leads to the same behavior - eventually, the sequence trickles down to the cycle 4-2-1.  But it's unproven if this is true for ALL numbers... it just works for all of the billions tested so far. :D  And sometimes it takes a while for the sequence to get down to that cycle.  For example, our TA chose to start with the number 231 which has a sequence that goes for 127 steps before cycling.

I want to try a similar session out with an older group and combine it with logic tables of pairity. :)  And I think this might be the last part of an "infinity" curriculum that I've been trying to piece together! :D

20141016_180015 20141016_181753 20141016_181547
ch3cooh: (Ball Pit)
Weighing "Failing Gracefully" highly is one of the best strategies I picked up in college.  It means that among many options for how to do things, giving a strong priority (a "weight") to those that, even if they don't reach fruition, still make a significant positive impact.  Projects that have zero utility until they are completely finished are dangerous - because in reality, few things have the chance to finish before the world changes around them making a 'perfect finish' impossible.  And with a limited amount of time to work on projects, it's also a huge deal when the partial project, put on hold, still has utility in that state.

Last night I ran into a project that has the highest potential to succeed /and/ to fail gracefully that I'ves seen in a long time.  It's not a new idea.  It's simply a local school that wants me to come in once a week for 4 hours to do 4 sequential classes, one with part of each grade.  And the concurrent math classes would be split so that students who need more support with the current school unit have a much higher student to teacher ratio, while students who are ready to move on don't get board/distract the class - instead they come to my session and do something likely related to their teachers' curriculum - but open ended research and problem-solving centric. :)

This role has about 60% of what appealed to me about working at MoMath - outreach to students who might not yet know that math is awesome, non-traditional curricula, visibilty to other teachers and scalability.  And then it also has some remarkable positive differences - that I'd be working with the same group of students, building a community and relationships with them over an entire year for instance.  Also, more freedom in what and how to teach.  And it's /so/ tempting that the scalability is still there... just doing this for 4-5 schools myself is a lifelong career that I think I'd be pretty happy with, in part because of how much free time it would leave me with to do any projects I saw fit to do.  :)  But, the large scale dream would be collecting people to do this with me - maybe from the math-circle teaching community.  The MC lesson plans are a good fit, and what I'm doing now -- developing MC-style lesson plans that can parellel core 'school-content' could be useful to other people.  I can see life that I would really like in this -- teaching 2-3 days/week, and coordinating the administration of a dozen people doing similarly, observing their classes 2-3 days/week.  Constantly building and rebuilding lessons to fit what new schools and teachers are doing. Working with teachers to expand their regular curriculum with the support of these weekly sessions.  :D  Wow -- it'a a position and a lifestyle that meets almost every metric I've got.

So yeah, I'm excited.  And... I think there's only a 5, maybe 10 percent chance that what I'm describing above actually happens.  But the failure is doing this myself at one school and then it doesn't go further than that.  And that 'failure' is also OK - very OK.  A lot of what I'm doing right now is like this -- I'm not sure what part will 'take off' if any, but the partial steps -- teaching for a lot of Math Circles and trying out other types of teaching/tutoring as well - the partial steps are also good things.  :)
ch3cooh: (Yosemite)
In short: a month ago today, the New Museum of Mathematics opened in Manhattan, NY. 
Soon after that, I received an email with this video of the MoMath Opening
Soon after that, I applied... then an interview :) ... then a job offer :D... and, a couple days ago, I accepted the offer! :D!!!
I'm going to be an Education Coordinator at the museum starting in February!
I'm planning to move to an apt off the PATH line in New Jersey, since PATH drops right into Manhattan at Madison Sq. Park where the museum is located.
So if you want to visit me and/or the new museum sometime after March 1st, just email me regarding 'crash space'.  I <3 NY, but It's more than a little terrifying to be uprooting and relocating so suddenly! I am definitely going to miss friends in Boston, and I'd love to have you all visit! 

More About the Museum (and PICTURES!) )


Dec. 12th, 2012 12:12 pm
ch3cooh: (Yosemite)

Interested in mathematical origami or Swedish folk music?  How about online education or filmmaking?  If so, you might want to take a look at the project I'm working on, a site at  It's a page of video-lessons organized in 2 trees of subject matters: "Swedish Folk Music" and "Origami Design."


First of all, I hope you just think it's pretty.  I had a lot of fun doing the art - and the visual metaphore is that 'topics' are trees suspending glowing spheres: 'concepts' so to speak.  I'm not enough of an artist to fully demonstrate how beautiful this idea looks to me:  a forrest, (perhaps more like a garden for the variety ;-) full of softly glowing spheres connected by strings of smaller lights, like a neural network of lights draped over a living forrest.  If I could, I'd make a video in which you zoom out now and see that this lit forrest is itself inside a glowing sphere with thin lines connecting it to nearby concepts in aesthetics, education, and engineering:

So, in that order:


And more feedback/recomendations/insights on what's up already would, of
course, be appreciated!  So comment or email me if you have ideas! :)

ch3cooh: (light on black water)
I'm about to teach a summer math course: Proofs and Visualizations (it's gonna be awesome!) and I've been talking about the problems/units with a bunch of friends.  One of the units is based on a math puzzle called "The Paradox of Perfectly Logical Pirates"  I've outlined the problem below.  However, here's the glitch - once you've come up with the straight-forward answer, here's another question:  Two twin brothers, Alfie and Ben are given $10 of allowance every week.  More specifically, Alfie's given the money and his father tells him to split it between himself and his brother Ben.  As long as Ben accepts the split, the boys get to keep the allowance, but if Ben ever complains, neither boy will get anything.  Alfie and Ben are logical kids, and both realize that something is better than nothing.  So, each week, Alfie gives Ben $1 and keeps $9 for himself.  And Ben doesn't complain because $1 is better than nothing.  But then, one day, Ben goes over to his friend David's house.  David's twin sister, Kate, has just been given $10 allowance to split between herself and David - their father has the exact same rules.  Perhaps David is more sure of himself or something, because he's decided that he'll reject the split unless his sister Kate gives him $5.  Since Kate wants to keep getting allowance ($5 is better than nothing) - she splits the money evenly between them each week.  Ben sees this and is surprised and impressed.  Can he get the same results from his brother Alfie?  Later that week, Ben visits his friend Fanny's house, although Ben doesn't like Fanny all that much - she's  a bit greedy and reminds Ben of his brother Alfie.  When Fanny's brother Elmo gets $10 of allowance to split between the two of them, Fanny tells Elmo that she'll complain to father unless Elmo gives her $9.  Elmo believes her (she is a greedy one) and would rather get $1 than nothing, so each week he gives Fanny $9.  Sometimes Ben wonders if he could get Alfie to do this for a while at least - just in order to pay him back for the many weeks of taking $9 for himself. 

In real life, who has the power? - the person splitting the money, or the most stubborn and greedy player? Why?  How can this question be described rigorously mathematically? 

The Paradox
of Perfectly Logical Pirates )

I'm really thrown by these puzzles/'paradoxes' and I feel like there's got to be a good theory somewhere to explain what's going on.  I also think these questions are practically relevant since they suggest that things like mutinies might have a logical basis, whereas simple economic theory frequently predicts that the masses will just accept their short-changed fate. 
ch3cooh: (SUCCESS!)
I'm working with a friend, Reena, on a teacher-training video series for ESP and the first video which I am mainly responsible for producing is "Things that should increase with class difficulty" We were talking about this at 4am today and, since one of the sub-topics is writing a good class description, we were talking about the effect of adding "Hardcore" to a class title.  Earlier... yesterday?... one of my students had suggested that I should have called my class "Cannibalism" instead of Theoretical Computer Science, since that would have attracted more students and since the class features a proof of the incomputability of the halting problem via a carefully constructed turring machine running on its own encoding. <om nom nom> In any case, in the last hour, these two ideas have solidified into an awesome class that I'm going to teach for Splash this year:

Hardcore Cannibalism: The Mathematics of Things That Eat Themselves
Description:  <om nom nom.>

  Fractals (in particular escape time fractals with recurrence relations, like the Mandelbrot set)
  A VERY brief sketch of that proof of the halting problem
Recursive definitions (definitions which contain parts of themselves, like the Fibonacci numbers) and recursive algorithms and, of coruse
  The paradox of self-containing sets

Thus far, these topics are fairly arbitrarily chosen... although reena and I both found it a bit odd that most of the math I teach would fit into this class in some sense.  In any event, if you have ideas or math-topics that I should ad to the above list, comment to this post.  Thanks!
Delta: from Robert Assalay no less - Newton's Method of Approximation, to the extent that it can be done without calculus. :)
ch3cooh: (Fringes of Chaos)
 On Friday, I taught for Proveit! (an ESP program where a MIT student teaches math at a local middle school for an hour once a week) and it was such a beautiful day outside that, 20 minutes before the class needed to start, I decided to scratch the planned topic and make a lecture that I could teach outside using sidewalk chalk (and where the students also get to play with sidewalk chalk a lot).  After a couple minutes, I decided that Graph Theory was excellent - and, in the 15 minutes walking over, this lecture sprang into my head as an awesome introduction with a very simple overlaying theme - 5, 4, 3, 2, 1, Graph Theory!. 

I started the lecture with a very basic introduction to what a graph is - verticies, edges, faces, and then the idea of embedding a graph in the plane. Students get to use their chalk a bit here - example: draw one possible embedding of K4 - and it's clear that there are distinctly different ones.  Then we start on the theme: counting down to GRAPH THEORY! == FIVE is a very simple 'proof' that K5 is non-planar.  It's really just intended as an example to show that non-planar graphs are possible.  (online explanation).  Then I introduce the FOUR color theorem and explain that no 'elegant' proof is known - the students get to test it of course, drawing and coloring graphs for each other.  Then, I ask them to prove that K3,3 is non-planar, although the problem is explained as the THREE houses THREE utilities problem. cute digression ) And this sets up Euler's formula V-E+F=TWO and a simple proof with some hints that expanding this idea to graphs embedded on a Taurus is interesting.  (so, that's the FIVE, FOUR, THREE, and TWO)

And now... now I need an awesome conclusion with a surprising ONE, and I can't think of anything.  The ideal would be where the one comes from nowhere - like, if each face of a polyhedron could be labeled with a positive or negative fraction somehow so that they all add up to 1... *sigh* I don't know - I just need something EXCITING (and preferably that can be demonstrated or tested with sidewalk chalk) to end the class!  All ideas welcome and appreciated! I have till this upcoming Friday to figure out how to end the class!
ch3cooh: (Biology and Astrobiology)
Notes I think I have learned about teaching (what I think I should do better)
(suggestions /very/ welcome)

1) Devote some time in the first few days to /really/ trying to figure out how the students think about the subject, then work to make ends meet
2) Have handouts with important lecture notes - including the formulas in assignments
3) Assignments should be a piece of paper physically given to students and projects should be a sheet of instructions and a sheet of grading keys
4) Review the last class in the first quarter of the next.
5) Give the students large blocks of time to work on things during class
6) Set up organization early on - ways for students to contact you, keeping track of the questions you can't answer without research

they'll be more later, this is just what I can think of in my insomnia now.
ch3cooh: (Fringes of Chaos)
Nice!  My HSSP students are SO shiny!  Fringes of Chaos II is officially on for next spring.  I mean, I gave them this:

IFS Fractals, Hausdorff Dimension, Topological Dimension, The Mandelbrot Set, The Chaos Game, Fractals In nature, Colors of Noise, Neural Nets, Intro to Cellular Automata, The game of Life, Fractals in Literature, Fractals in Ancient Art and Architecture,  Rigorously Defined Chaos, Significant Dependence on Initial Conditions, Strange Attractors, The Logistic Equation, Lorenz's Water Wheel, Shannon's Coding, Rigorously Defined Information Entropy, The Philosophy of Entropy in Physics, The Carnot Engine, and Arcadia, by Tom Stoppard

and they still want more!  And so this:

More Information Theory, Statistical Mechanics (thermo), Intro to Continuum Systems, Theory of Computation, Turing machines, Boolean analysis, Computability, Time and Space complexity of algorithms, Decidability, the Halting Problem, Complexity Theory, Interactive proof systems, Non Deterministic Computational Models, and I'll probably throw in some lambda calculus, Godel's Incompleteness, Goldbach's conjecture, and then ending with the edge of Quantum and bounds of Information transfer in physics

is the course I get to prep.
And we're reading through and discussing Godel, Escher, Bach: An Eternal Golden Braid over the summer. :-)

Aaaaah!  My students rock so much!  This class is going to be awesome!!
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