## Trying to find math inside everything else

### The MTBoS Genome Project

Have you ever listened to Pandora and wondered what method they used to determine what songs to play for you? I did and remember writing a research paper about it back in grad school.

Pandora makes use of something called the Music Genome Project. Professional musicians will actually listen to every song in their database and tag all of the songs along different dimensions – timbre of the instruments, vocal type, volume, bpm, etc. Each song then gets a vector associated with it where each dimension is one of those categories.

Then, when you put in a seed song, Pandora will calculate the closest songs to your seed, basically using the distance formula in hundreds of dimensions. (There’s some weighting and tweaking, of course, but that’s the core premise.)

At the Sunday My Favorites session of TMC14, Bob Lochel and Megan Schmidt show us how to find our closest buddies by filling out a survey about what movies they like. Then they calculated the correlation coefficient and the people who correlated the most were the best friends of the pair.

On Saturday, I was talking with someone (I think it was Matt Baker) about how to help people get into our community. He mentioned that while there are a lot of good ideas out there, the ideas that resonate the most with him are the ones that comes from they people he most identified with – whose teaching style was most like his. I had the idea that we could somehow make a survey that a new person could fill out and it would give them a personalized output of Twitter accounts and blogs to follow – a somewhat advanced version of the category lists we made here during TMC12.

I want to make this, but I need help. What are the dimensions that we should ask about? What are important aspects of your teacher identity, and what are some of the things that make you feel on the same wavelength as another teacher in the MTBoS? Please let me know so I can start compiling these dimensions and building this.

(Also, if there is anyone more skilled in programming who is willing to help me, ping me.)

### Set Building Game

So I came up with this semi-game last year, based on Frank Noschese’s Subversive Lab Grouping activity. My students had already done that activity at the beginning of the year, so they were familiar with the cards and the idea that the groups were not always what they appeared.

This time, I gave each student a badge that had two words on it: one word on the front, and one word on the back. I asked the students to create groups of 3-4 students using either of their two words. After they formed a group, they had to come up with a description of their group that applied to ALL of their members but ONLY to their members.

This was tricky because of the set of words that I chose, which I had displayed at the front of the room.

Almost any group of 4 you could create would have some errant fifth member that would fit. And I was VERY adamant that they could not have more than 4 people in a group, no matter how much they asked. So the students needed to use set operations to include or exclude other words. For example, if the students were {Arizona, Brooklyn, Georgia, Virginia} they might say “Our group is the set of x such that x is a girl’s name AND x is a location AND x is NOT Asian.”

Often students would give sentences that weren’t quite precise enough, so I (and later other students in the class) would push back. “Wait! China is a girl’s name and a location.” “Okay, so we’ll add ‘AND x is not Asian.” This caused them to think deeply about what the actual definitions of their group were, and to be careful with being precise. If they weren’t precise enough, they would let other words into their group.

After we got the gist, the groups would then either come up with a description and see if the other students could guess their members OR list their members and see if the other students could figure our their description.

Each round, I had the groups write down on an accompanying sheet their group in Roster Notation, Set Builder Notation, and draw a Venn Diagram where they shaded in where their group lies. So through this I introduce the different notation we use, intersections, and complements. (That left only unions and interval notation for the next day.) I also included pictures of 4-way and 5-way Venn diagrams, in case they needed it.

### Stuff

Set Cards (pdf – formatted for name-tag size)

Set Game Worksheet (pdf)

Set Game Worksheet (pages)