Tuesday, February 25, 2014


Earlier this week, we started inference with means, which is the last unit before Spring Break. (Translation: this is when it starts to feel like you are pulling teeth from a chicken.)1

Here’s one of the first “problems” that we explore:

Photo Feb 25, 8 03 12 AM

Of course, to investigate this claim,2 we need actual “data”:

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Yes. I brought cookies.3

Each student gets one cookie45 and counts the number of chips6 in their piece of “data”,7 then writes that number on the board, like so:

Chips Count

Sounds like fun, no? 8

. . .

That is, of course, until the following class, when I pose the following question, merely as a matter of academics…

Photo Feb 25, 8 02 34 AM

…only to have a student ask aloud with enthusiastic anticipation:

Did you bring us donuts today?!!

. . .

. . .


  1. That’s just a metaphor, by the way, I have zero experience with actually pulling teeth from chicken. []
  2. By the way, I totally made up the claimed value of “24 chips per cookie”… if you represent Nabisco, I meant no harm. []
  3. All in the name of Statistics, of course. []
  4. er… piece of “data” []
  5. incidentally, the students gets their clickers at the start of class and the warm up question simply states, “Choose from the following: Chewy, Crispy, or Chunky” – and this dictates the type of Chips Ahoy that they get – Chewy, Original, or Chunky. Generally, the classes that choose from the latter two end up regretting it =) []
  6. rounded to the nearest whole number, please []
  7. At which point you hear cries of “oh my gosh, you’re not DOING it right, there are chips INSIDE the cookie! You have to rip it apart!!!”… followed by “Please. I just want to be able to enjoy eating my data.” []
  8. If you’re curious, the classes all decided that a 2-tailed test was appropriate given the prompt, and the jury was split – 2 classes rejected the Ho, while the other 2 failed to reject. []