Hoping I’m not behind, just on a different path

Oh, thank you Kate, for your latest post, from which all this flows. It’s reassuring that the luminaries, the veterans of this biz, are facing some of the same demons I am. It’s also profoundly scary to know that they will not go away (the demons, not the luminaries). At any rate, musing on her post made me think about the various ways that we are all tacking against strong prevailing winds.

And isn’t that a noble calling: to buck the system, to stick it to The Man? Sure is, but it only counts if what we do actually works. And that’s why good assessment is such a sterilizing light; as the punk said, we gots to know.

So, to the nitty-gritty. I teach “regular” stats; my colleague teaches “honors” stats. He sent me some problems he was giving to his kids. Here’s one:

A market research company employs a large number of typists to enter data into a computer. The time taken for new typists to learn the computer system is known to have a normal distribution with a mean of 90 minutes and a standard deviation of 18 minutes. The proportion of new typists that take more than two hours to learn the computer system is

A) 0.048

B) 0.394

C) 0.452

D) 0.548

E) 0.952

If you are appalled, let me say that it is not his fault: if you were an AP Stat teacher, you would recognize this sort of thing as preparation for the AP exam. The Normal distribution is Chapter 2 in the book, and the exam has questions like this.

But if you are not appalled, let me try to convince you at least to be uncomfortable: Who are they kidding? Do you really think that some company knows this mean and standard deviation? How do they assess when a typist “knows” the new computer system? Do they really have enough data to establish whether the distribution is Normal? And why, in this day and age, does this company use an army of typists for data entry? [see note at end of post]

Doesn’t that argument sound good? Yeah! All power to realistic contexts! Promote authenticity! Stick it to The Man!

But here’s what really went on in my head when I read that problem:

“OMG, I’m so far behind.”

Continue reading Hoping I’m not behind, just on a different path

In it up to here

I know (self), I know, I’m behind in recording what’s going on! Let me just say here that I just handed back the first quiz, the first artifact that fits with SBG, and you know what? It felt pretty good. Everybody nodded in the right places when I explaind that “what’s it out of?” was maybe not the right question, even though a good answer is “4.”

The next quiz is Tuesday—I wanted to follow up immediately with a way for them to see how demonstrating mastery works—and I have just shipped off some practice problems. We’re redoing the material from the first quiz—the first three learniong goals—and adding one learning goal (rates), this one with items written by them in class today as part of the prep.

Meanwhile, it’s Back to School Night, which is traditionally one of my favorite events; I only hope I’ll be awake, as the last few have been Bad Sleep Nights, dominated by my having Dvorak Symphony #7 stuck in my head (only the first 8 or so bars, over and over, so not an interesting intracranial concert) and my revisiting a memo I wrote to the head of school about our evolving mission statement. The mission-statement process got me all het up the way you can get upset by comments you diagree with on political blog posts, when you feel compelled to write some pithy, intelligent, counter-comment. Unlike in the poliblog situation, however, our comments may actually have an effect, so I took the time to write carefully about it, which makes me a good citizen and community member—but the damned thing wouldn’t let me get to sleep.

Some things I need to write about soon:

  • The first “Claim” assignment and its revisions. I’m really pleased with it, although I’m not sure what people learn from it.
  • The need to say less and less and less. I know this, why do I have such trouble doing it?

Enough for now! Time to go find the food and set up my room!

A First “Claim” Investigation

A slide showing another version of the instructions

These are something like the entire instructions for a mini-investigation that has taken much of the second and third of our class meetings:

Mess around with U S Census data in Fathom until you notice some pattern or relationship. Then make a claim: a statement that must be either true or false. Then create a visualization (in this case, a graph) that speaks to your claim. Then make one or two sentences of commentary. These go onto one or two PowerPoint slides.

The purpose is severalfold:

  • You get chance to play with the data
  • You learn more Fathom features, largely by induction or osmosis or something; in any case, you learn them when you need them
  • You get to direct your own investigation
  • You get practice communicating in writing—or at least slideSpeak
  • I get to see how you do on all these things
  • We all get to try out the online assignment drop-box

In fact, it has gone pretty well. We started on Wednesday (the second class) with my demonstrating how to get anything other than the default variables. I modeled the make-a-claim and make-a-graph part by showing how to compare incomes between men and women.

Continue reading A First “Claim” Investigation

Survived Day One

The Census Age/Marital-Status Dance. Sample of what we did during the Fathom part of the block. Click to expand if it's illegible.


I have been agonizing (all my friends and family will corroborate) about what to say and do on the first day. A lot of the worry has been about how to set the right tone. If we’re going to try to play the whole game (Perkins; Buell), I want the kids to know right away the game we will be playing. Which meant I had to decide what that was: what do I think is most important for them to learn?

Well. I survived the first class. Some things went better than others. But I want to acknowledge here two good decisions I made.

Background: the whole school is going through a re-writing of the mission statement. There is even a mission statement task force, on which I thankfully do not serve. But despite how horrendously dreary and time-wasting mission statements can be, I was surprised that I actually like the new mission statement a lot. It accomplishes its purpose well. With that in mind, could I capture what’s important in a couple of sentences? Make a stat class mission statement?

Here’s what I came up with after thinking about a lot of different (and probably equivalent) ways to carve up the territory:

In this class, you will

  • Learn to make effective and valid arguments using data
  • Become a critical consumer of data

Continue reading Survived Day One